diff --git a/runtime/vm/bootstrap.cc b/runtime/vm/bootstrap.cc
index a6e9a270bf5..5a10c653461 100644
--- a/runtime/vm/bootstrap.cc
+++ b/runtime/vm/bootstrap.cc
@@ -367,8 +367,8 @@ static RawError* BootstrapFromKernel(Thread* thread, kernel::Program* program) {
     dart_name = library.url();
     for (intptr_t j = 0; j < program->libraries().length(); ++j) {
       kernel::Library* kernel_library = program->libraries()[j];
-      kernel::String* uri = kernel_library->import_uri();
-      const String& kernel_name = reader.DartSymbol(uri);
+      intptr_t uri_index = kernel_library->import_uri();
+      const String& kernel_name = reader.DartSymbol(uri_index);
       if (kernel_name.Equals(dart_name)) {
         reader.ReadLibrary(kernel_library);
         library.SetLoaded();
diff --git a/runtime/vm/bootstrap_nocore.cc b/runtime/vm/bootstrap_nocore.cc
index 44cff902480..4176d0595d4 100644
--- a/runtime/vm/bootstrap_nocore.cc
+++ b/runtime/vm/bootstrap_nocore.cc
@@ -95,8 +95,8 @@ RawError* BootstrapFromKernel(Thread* thread, kernel::Program* program) {
     dart_name = library.url();
     for (intptr_t j = 0; j < program->libraries().length(); ++j) {
       kernel::Library* kernel_library = program->libraries()[j];
-      kernel::String* uri = kernel_library->import_uri();
-      const String& kernel_name = reader.DartSymbol(uri);
+      intptr_t uri_index = kernel_library->import_uri();
+      const String& kernel_name = reader.DartSymbol(uri_index);
       if (kernel_name.Equals(dart_name)) {
         reader.ReadLibrary(kernel_library);
         library.SetLoaded();
diff --git a/runtime/vm/kernel.cc b/runtime/vm/kernel.cc
index 4ec55e15245..001d4506f6b 100644
--- a/runtime/vm/kernel.cc
+++ b/runtime/vm/kernel.cc
@@ -31,7 +31,7 @@ SourceTable::~SourceTable() {
 
 
 CanonicalName::CanonicalName()
-    : parent_(NULL), name_(NULL), is_referenced_(false) {}
+    : parent_(NULL), name_index_(-1), is_referenced_(false) {}
 
 
 CanonicalName::~CanonicalName() {
@@ -46,10 +46,10 @@ CanonicalName* CanonicalName::NewRoot() {
 }
 
 
-CanonicalName* CanonicalName::AddChild(String* name) {
+CanonicalName* CanonicalName::AddChild(intptr_t name_index) {
   CanonicalName* child = new CanonicalName();
   child->parent_ = this;
-  child->name_ = name;
+  child->name_index_ = name_index;
   children_.Add(child);
   return child;
 }
@@ -1231,7 +1231,7 @@ void FunctionType::VisitChildren(Visitor* visitor) {
   VisitList(&type_parameters(), visitor);
   VisitList(&positional_parameters(), visitor);
   for (int i = 0; i < named_parameters().length(); ++i) {
-    named_parameters()[i]->second()->AcceptDartTypeVisitor(visitor);
+    named_parameters()[i]->type()->AcceptDartTypeVisitor(visitor);
   }
   return_type()->AcceptDartTypeVisitor(visitor);
 }
diff --git a/runtime/vm/kernel.h b/runtime/vm/kernel.h
index 1ebd8f0ad5c..a7950be8d39 100644
--- a/runtime/vm/kernel.h
+++ b/runtime/vm/kernel.h
@@ -243,66 +243,6 @@ class TypeParameterList : public List<TypeParameter> {
 };
 
 
-template <typename A, typename B>
-class Tuple {
- public:
-  static Tuple<A, B>* ReadFrom(Reader* reader);
-
-  Tuple(A* a, B* b) : first_(a), second_(b) {}
-
-  A* first() { return first_; }
-  B* second() { return second_; }
-
- private:
-  Tuple() {}
-
-  Ref<A> first_;
-  Child<B> second_;
-
-  DISALLOW_COPY_AND_ASSIGN(Tuple);
-};
-
-
-class String {
- public:
-  // Read a string reference, which is an index into the string table.
-  static String* ReadFrom(Reader* reader);
-
-  // Read a string implementation given its size.
-  static String* ReadRaw(Reader* reader, intptr_t size);
-
-  String(intptr_t offset, int size) : offset_(offset), size_(size) {}
-
-  intptr_t offset() { return offset_; }
-  int size() { return size_; }
-
-  bool is_empty() { return size_ == 0; }
-
- private:
-  intptr_t offset_;
-  int size_;
-
-  DISALLOW_COPY_AND_ASSIGN(String);
-};
-
-
-class StringTable {
- public:
-  void ReadFrom(Reader* reader);
-
-  List<String>& strings() { return strings_; }
-
- private:
-  StringTable() {}
-
-  friend class Program;
-
-  List<String> strings_;
-
-  DISALLOW_COPY_AND_ASSIGN(StringTable);
-};
-
-
 class Source {
  public:
   ~Source();
@@ -390,12 +330,12 @@ class CanonicalName {
  public:
   ~CanonicalName();
 
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   CanonicalName* parent() { return parent_; }
   bool is_referenced() { return is_referenced_; }
   void set_referenced(bool referenced) { is_referenced_ = referenced; }
 
-  CanonicalName* AddChild(String* string);
+  CanonicalName* AddChild(intptr_t string_index);
 
   static CanonicalName* NewRoot();
 
@@ -403,7 +343,7 @@ class CanonicalName {
   CanonicalName();
 
   CanonicalName* parent_;
-  String* name_;
+  intptr_t name_index_;
   MallocGrowableArray<CanonicalName*> children_;
   bool is_referenced_;
 
@@ -488,9 +428,9 @@ class Library : public LinkedNode {
   virtual void AcceptTreeVisitor(TreeVisitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  String* import_uri() { return import_uri_; }
+  intptr_t import_uri() { return import_uri_index_; }
   intptr_t source_uri_index() { return source_uri_index_; }
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   List<Typedef>& typedefs() { return typedefs_; }
   List<Class>& classes() { return classes_; }
   List<Field>& fields() { return fields_; }
@@ -500,13 +440,13 @@ class Library : public LinkedNode {
   intptr_t kernel_data_size() { return kernel_data_size_; }
 
  private:
-  Library() : name_(NULL), kernel_data_(NULL), kernel_data_size_(-1) {}
+  Library() : name_index_(-1), kernel_data_(NULL), kernel_data_size_(-1) {}
 
   template <typename T>
   friend class List;
 
-  Ref<String> name_;
-  Ref<String> import_uri_;
+  intptr_t name_index_;
+  intptr_t import_uri_index_;
   intptr_t source_uri_index_;
   List<Typedef> typedefs_;
   List<Class> classes_;
@@ -531,7 +471,7 @@ class Typedef : public LinkedNode {
   virtual void VisitChildren(Visitor* visitor);
 
   Library* parent() { return parent_; }
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   intptr_t source_uri_index() { return source_uri_index_; }
   TokenPosition position() { return position_; }
   TypeParameterList& type_parameters() { return type_parameters_; }
@@ -545,7 +485,7 @@ class Typedef : public LinkedNode {
   friend class List;
 
   Ref<Library> parent_;
-  Ref<String> name_;
+  intptr_t name_index_;
   intptr_t source_uri_index_;
   TokenPosition position_;
   TypeParameterList type_parameters_;
@@ -565,7 +505,7 @@ class Class : public LinkedNode {
   virtual void AcceptClassVisitor(ClassVisitor* visitor) = 0;
 
   Library* parent() { return parent_; }
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   intptr_t source_uri_index() { return source_uri_index_; }
   bool is_abstract() { return is_abstract_; }
   List<Expression>& annotations() { return annotations_; }
@@ -585,7 +525,7 @@ class Class : public LinkedNode {
   friend class List;
 
   Ref<Library> parent_;
-  Ref<String> name_;
+  intptr_t name_index_;
   intptr_t source_uri_index_;
   bool is_abstract_;
   List<Expression> annotations_;
@@ -1291,8 +1231,8 @@ class NamedExpression : public TreeNode {
  public:
   static NamedExpression* ReadFrom(Reader* reader);
 
-  NamedExpression(String* name, Expression* expr)
-      : name_(name), expression_(expr) {}
+  NamedExpression(intptr_t name_index, Expression* expr)
+      : name_index_(name_index), expression_(expr) {}
   virtual ~NamedExpression();
 
   DEFINE_CASTING_OPERATIONS(NamedExpression);
@@ -1300,13 +1240,13 @@ class NamedExpression : public TreeNode {
   virtual void AcceptTreeVisitor(TreeVisitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   Expression* expression() { return expression_; }
 
  private:
   NamedExpression() {}
 
-  Ref<String> name_;
+  intptr_t name_index_;
   Child<Expression> expression_;
 
   DISALLOW_COPY_AND_ASSIGN(NamedExpression);
@@ -1579,17 +1519,17 @@ class StringLiteral : public BasicLiteral {
 
   virtual void AcceptExpressionVisitor(ExpressionVisitor* visitor);
 
-  explicit StringLiteral(String* string) : value_(string) {}
+  explicit StringLiteral(intptr_t string_index) : value_index_(string_index) {}
   virtual ~StringLiteral();
 
   DEFINE_CASTING_OPERATIONS(StringLiteral);
 
-  String* value() { return value_; }
+  intptr_t value() { return value_index_; }
 
  protected:
   StringLiteral() {}
 
-  Ref<String> value_;
+  intptr_t value_index_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(StringLiteral);
@@ -1602,7 +1542,7 @@ class BigintLiteral : public StringLiteral {
 
   virtual void AcceptExpressionVisitor(ExpressionVisitor* visitor);
 
-  explicit BigintLiteral(String* string) : StringLiteral(string) {}
+  explicit BigintLiteral(intptr_t string_index) : StringLiteral(string_index) {}
   virtual ~BigintLiteral();
 
   DEFINE_CASTING_OPERATIONS(BigintLiteral);
@@ -1646,12 +1586,12 @@ class DoubleLiteral : public BasicLiteral {
 
   virtual void AcceptExpressionVisitor(ExpressionVisitor* visitor);
 
-  String* value() { return value_; }
+  intptr_t value() { return value_index_; }
 
  private:
   DoubleLiteral() {}
 
-  Ref<String> value_;
+  intptr_t value_index_;
 
   DISALLOW_COPY_AND_ASSIGN(DoubleLiteral);
 };
@@ -1706,12 +1646,12 @@ class SymbolLiteral : public Expression {
   virtual void AcceptExpressionVisitor(ExpressionVisitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  String* value() { return value_; }
+  intptr_t value() { return value_index_; }
 
  private:
   SymbolLiteral() {}
 
-  Ref<String> value_;
+  intptr_t value_index_;
 
   DISALLOW_COPY_AND_ASSIGN(SymbolLiteral);
 };
@@ -2619,7 +2559,7 @@ class VariableDeclaration : public Statement {
   bool IsConst() { return (flags_ & kFlagConst) == kFlagConst; }
   bool IsFinal() { return (flags_ & kFlagFinal) == kFlagFinal; }
 
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   DartType* type() { return type_; }
   Expression* initializer() { return initializer_; }
   TokenPosition equals_position() { return equals_position_; }
@@ -2635,7 +2575,7 @@ class VariableDeclaration : public Statement {
   friend class List;
 
   word flags_;
-  Ref<String> name_;
+  intptr_t name_index_;
   Child<DartType> type_;
   Child<Expression> initializer_;
   TokenPosition equals_position_;
@@ -2680,14 +2620,15 @@ class Name : public Node {
   virtual void AcceptVisitor(Visitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  String* string() { return string_; }
+  intptr_t string_index() { return string_index_; }
   CanonicalName* library() { return library_reference_; }
 
  private:
-  Name(String* string, CanonicalName* library_reference)
-      : string_(string), library_reference_(library_reference) {}  // NOLINT
+  Name(intptr_t string_index, CanonicalName* library_reference)
+      : string_index_(string_index),
+        library_reference_(library_reference) {}  // NOLINT
 
-  Ref<String> string_;
+  intptr_t string_index_;
   Ref<CanonicalName> library_reference_;  // Library.
 
   DISALLOW_COPY_AND_ASSIGN(Name);
@@ -2820,6 +2761,26 @@ class TypedefType : public DartType {
 };
 
 
+class NamedParameter {
+ public:
+  static NamedParameter* ReadFrom(Reader* reader);
+
+  NamedParameter(intptr_t name_index, DartType* type)
+      : name_index_(name_index), type_(type) {}
+
+  intptr_t name() { return name_index_; }
+  DartType* type() { return type_; }
+
+ private:
+  NamedParameter() : name_index_(-1) {}
+
+  intptr_t name_index_;
+  Child<DartType> type_;
+
+  DISALLOW_COPY_AND_ASSIGN(NamedParameter);
+};
+
+
 class FunctionType : public DartType {
  public:
   static FunctionType* ReadFrom(Reader* reader);
@@ -2835,9 +2796,7 @@ class FunctionType : public DartType {
   TypeParameterList& type_parameters() { return type_parameters_; }
   int required_parameter_count() { return required_parameter_count_; }
   List<DartType>& positional_parameters() { return positional_parameters_; }
-  List<Tuple<String, DartType> >& named_parameters() {
-    return named_parameters_;
-  }
+  List<NamedParameter>& named_parameters() { return named_parameters_; }
   DartType* return_type() { return return_type_; }
 
  private:
@@ -2846,7 +2805,7 @@ class FunctionType : public DartType {
   TypeParameterList type_parameters_;
   int required_parameter_count_;
   List<DartType> positional_parameters_;
-  List<Tuple<String, DartType> > named_parameters_;
+  List<NamedParameter> named_parameters_;
   Child<DartType> return_type_;
 
   DISALLOW_COPY_AND_ASSIGN(FunctionType);
@@ -2904,7 +2863,7 @@ class TypeParameter : public TreeNode {
   virtual void AcceptTreeVisitor(TreeVisitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  String* name() { return name_; }
+  intptr_t name() { return name_index_; }
   DartType* bound() { return bound_; }
 
  private:
@@ -2914,7 +2873,7 @@ class TypeParameter : public TreeNode {
   friend class List;
   friend class TypeParameterList;
 
-  Ref<String> name_;
+  intptr_t name_index_;
   Child<DartType> bound_;
 
   DISALLOW_COPY_AND_ASSIGN(TypeParameter);
@@ -2932,14 +2891,13 @@ class Program : public TreeNode {
   virtual void AcceptTreeVisitor(TreeVisitor* visitor);
   virtual void VisitChildren(Visitor* visitor);
 
-  StringTable& string_table() { return string_table_; }
   SourceTable& source_table() { return source_table_; }
   List<Library>& libraries() { return libraries_; }
   CanonicalName* main_method() { return main_method_reference_; }
   CanonicalName* canonical_name_root() { return canonical_name_root_; }
   MallocGrowableArray<MallocGrowableArray<intptr_t>*> valid_token_positions;
   MallocGrowableArray<MallocGrowableArray<intptr_t>*> yield_token_positions;
-  intptr_t string_data_offset() { return string_data_offset_; }
+  intptr_t string_table_offset() { return string_table_offset_; }
 
  private:
   Program() {}
@@ -2947,12 +2905,10 @@ class Program : public TreeNode {
   Child<CanonicalName> canonical_name_root_;
   List<Library> libraries_;
   Ref<CanonicalName> main_method_reference_;  // Procedure.
-  StringTable string_table_;
   SourceTable source_table_;
 
-  // The offset from the start of the binary to the start of the UTF-8 encoded
-  // string data.
-  intptr_t string_data_offset_;
+  // The offset from the start of the binary to the start of the string table.
+  intptr_t string_table_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(Program);
 };
@@ -2965,8 +2921,6 @@ class Reference : public AllStatic {
   static CanonicalName* ReadClassFrom(Reader* reader, bool allow_null = false);
 
   static CanonicalName* ReadTypedefFrom(Reader* reader);
-
-  static String* ReadStringFrom(Reader* reader);
 };
 
 
diff --git a/runtime/vm/kernel_binary.cc b/runtime/vm/kernel_binary.cc
index d38dd8b0563..8f63e6b05ee 100644
--- a/runtime/vm/kernel_binary.cc
+++ b/runtime/vm/kernel_binary.cc
@@ -87,12 +87,11 @@ void TypeParameterList::ReadFrom(Reader* reader) {
 }
 
 
-template <typename A, typename B>
-Tuple<A, B>* Tuple<A, B>::ReadFrom(Reader* reader) {
+NamedParameter* NamedParameter::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
-  A* first = A::ReadFrom(reader);
-  B* second = B::ReadFrom(reader);
-  return new Tuple<A, B>(first, second);
+  intptr_t name_index = reader->ReadUInt();
+  DartType* type = DartType::ReadFrom(reader);
+  return new NamedParameter(name_index, type);
 }
 
 
@@ -115,42 +114,6 @@ class VariableDeclarationImpl {
 };
 
 
-String* String::ReadFrom(Reader* reader) {
-  TRACE_READ_OFFSET();
-  return Reference::ReadStringFrom(reader);
-}
-
-
-String* String::ReadRaw(Reader* reader, intptr_t size) {
-  ASSERT(reader->string_data_offset() >= 0);
-  String* result =
-      new String(reader->offset() - reader->string_data_offset(), size);
-  reader->Consume(size);
-  return result;
-}
-
-
-void StringTable::ReadFrom(Reader* reader) {
-  TRACE_READ_OFFSET();
-  // Read the table of end offsets.
-  intptr_t length = reader->ReadUInt();
-  intptr_t* end_offsets = new intptr_t[length];
-  for (intptr_t i = 0; i < length; ++i) {
-    end_offsets[i] = reader->ReadUInt();
-  }
-  // Read the UTF-8 encoded strings.
-  reader->MarkStringDataOffset();
-  strings_.EnsureInitialized(length);
-  intptr_t start_offset = 0;
-  for (intptr_t i = 0; i < length; ++i) {
-    ASSERT(strings_[i] == NULL);
-    strings_[i] = String::ReadRaw(reader, end_offsets[i] - start_offset);
-    start_offset = end_offsets[i];
-  }
-  delete[] end_offsets;
-}
-
-
 void SourceTable::ReadFrom(Reader* reader) {
   size_ = reader->ReadUInt();
   sources_ = new Source[size_];
@@ -206,8 +169,8 @@ Library* Library::ReadFrom(Reader* reader) {
   kernel_data_size_ = reader->size();
 
   canonical_name_ = reader->ReadCanonicalNameReference();
-  name_ = Reference::ReadStringFrom(reader);
-  import_uri_ = canonical_name_->name();
+  name_index_ = reader->ReadUInt();
+  import_uri_index_ = canonical_name_->name();
   source_uri_index_ = reader->ReadUInt();
   reader->set_current_script_id(source_uri_index_);
 
@@ -240,7 +203,7 @@ Typedef* Typedef::ReadFrom(Reader* reader) {
 
   canonical_name_ = reader->ReadCanonicalNameReference();
   position_ = reader->ReadPosition(false);
-  name_ = Reference::ReadStringFrom(reader);
+  name_index_ = reader->ReadUInt();
   source_uri_index_ = reader->ReadUInt();
   type_parameters_.ReadFrom(reader);
   type_ = DartType::ReadFrom(reader);
@@ -255,7 +218,7 @@ Class* Class::ReadFrom(Reader* reader) {
   canonical_name_ = reader->ReadCanonicalNameReference();
   position_ = reader->ReadPosition(false);
   is_abstract_ = reader->ReadBool();
-  name_ = Reference::ReadStringFrom(reader);
+  name_index_ = reader->ReadUInt();
   source_uri_index_ = reader->ReadUInt();
   reader->set_current_script_id(source_uri_index_);
   reader->record_token_position(position_);
@@ -346,12 +309,6 @@ CanonicalName* Reference::ReadTypedefFrom(Reader* reader) {
 }
 
 
-String* Reference::ReadStringFrom(Reader* reader) {
-  int index = reader->ReadUInt();
-  return reader->helper()->program()->string_table().strings()[index];
-}
-
-
 Field* Field::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   kernel_offset_ = reader->offset();  // Notice the ReadTag() below.
@@ -719,9 +676,9 @@ Arguments* Arguments::ReadFrom(Reader* reader) {
 
 NamedExpression* NamedExpression::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
-  String* name = Reference::ReadStringFrom(reader);
+  intptr_t name_index = reader->ReadUInt();
   Expression* expression = Expression::ReadFrom(reader);
-  return new NamedExpression(name, expression);
+  return new NamedExpression(name_index, expression);
 }
 
 
@@ -842,7 +799,7 @@ AsExpression* AsExpression::ReadFrom(Reader* reader) {
 StringLiteral* StringLiteral::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   intptr_t offset = reader->offset() - 1;  // -1 to include tag byte.
-  StringLiteral* lit = new StringLiteral(Reference::ReadStringFrom(reader));
+  StringLiteral* lit = new StringLiteral(reader->ReadUInt());
   lit->kernel_offset_ = offset;
   return lit;
 }
@@ -851,7 +808,7 @@ StringLiteral* StringLiteral::ReadFrom(Reader* reader) {
 BigintLiteral* BigintLiteral::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   intptr_t offset = reader->offset() - 1;  // -1 to include tag byte.
-  BigintLiteral* lit = new BigintLiteral(Reference::ReadStringFrom(reader));
+  BigintLiteral* lit = new BigintLiteral(reader->ReadUInt());
   lit->kernel_offset_ = offset;
   return lit;
 }
@@ -880,7 +837,7 @@ DoubleLiteral* DoubleLiteral::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   DoubleLiteral* literal = new DoubleLiteral();
   literal->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
-  literal->value_ = Reference::ReadStringFrom(reader);
+  literal->value_index_ = reader->ReadUInt();
   return literal;
 }
 
@@ -906,7 +863,7 @@ SymbolLiteral* SymbolLiteral::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
   SymbolLiteral* lit = new SymbolLiteral();
   lit->kernel_offset_ = reader->offset() - 1;  // -1 to include tag byte.
-  lit->value_ = Reference::ReadStringFrom(reader);
+  lit->value_index_ = reader->ReadUInt();
   return lit;
 }
 
@@ -1384,7 +1341,7 @@ VariableDeclaration* VariableDeclaration::ReadFromImpl(Reader* reader,
   decl->position_ = reader->ReadPosition();
   decl->equals_position_ = reader->ReadPosition();
   decl->flags_ = reader->ReadFlags();
-  decl->name_ = Reference::ReadStringFrom(reader);
+  decl->name_index_ = reader->ReadUInt();
   decl->type_ = DartType::ReadFrom(reader);
   decl->initializer_ = reader->ReadOptional<Expression>();
 
@@ -1412,12 +1369,13 @@ FunctionDeclaration* FunctionDeclaration::ReadFrom(Reader* reader) {
 
 
 Name* Name::ReadFrom(Reader* reader) {
-  String* name = Reference::ReadStringFrom(reader);
-  if (name->size() >= 1 && reader->CharacterAt(name, 0) == '_') {
+  intptr_t name_index = reader->ReadUInt();
+  if ((reader->StringLength(name_index) >= 1) &&
+      (reader->CharacterAt(name_index, 0) == '_')) {
     CanonicalName* library_reference = reader->ReadCanonicalNameReference();
-    return new Name(name, library_reference);
+    return new Name(name_index, library_reference);
   } else {
-    return new Name(name, NULL);
+    return new Name(name_index, NULL);
   }
 }
 
@@ -1507,7 +1465,7 @@ FunctionType* FunctionType::ReadFrom(Reader* reader) {
   type->type_parameters().ReadFrom(reader);
   type->required_parameter_count_ = reader->ReadUInt();
   type->positional_parameters().ReadFromStatic<DartType>(reader);
-  type->named_parameters().ReadFromStatic<Tuple<String, DartType> >(reader);
+  type->named_parameters().ReadFromStatic<NamedParameter>(reader);
   type->return_type_ = DartType::ReadFrom(reader);
   return type;
 }
@@ -1549,9 +1507,22 @@ Program* Program::ReadFrom(Reader* reader) {
   program->canonical_name_root_ = CanonicalName::NewRoot();
   reader->helper()->set_program(program);
 
-  program->string_table_.ReadFrom(reader);
-  program->string_data_offset_ = reader->string_data_offset();
-  ASSERT(program->string_data_offset_ >= 0);
+  // Skip the table of string end offsets.
+  reader->MarkStringTableOffset();
+  intptr_t length = reader->ReadUInt();
+  reader->string_offsets_ = new intptr_t[length + 1];
+  intptr_t offset = 0;
+  for (intptr_t i = 0; i < length; ++i) {
+    reader->string_offsets_[i] = offset;
+    offset = reader->ReadUInt();
+  }
+  reader->string_offsets_[length] = offset;
+  // Skip the UTF-8 encoded strings.
+  reader->MarkStringDataOffset();
+  reader->Consume(offset);
+
+  program->string_table_offset_ = reader->string_table_offset();
+  ASSERT(program->string_table_offset_ >= 0);
   program->source_table_.ReadFrom(reader);
 
   int canonical_names = reader->ReadUInt();
@@ -1565,9 +1536,8 @@ Program* Program::ReadFrom(Reader* reader) {
       parent = program->canonical_name_root();
     }
     ASSERT(parent != NULL);
-    int name_index = reader->ReadUInt();
-    String* name = program->string_table().strings()[name_index];
-    CanonicalName* canonical_name = parent->AddChild(name);
+    intptr_t name_index = reader->ReadUInt();
+    CanonicalName* canonical_name = parent->AddChild(name_index);
     reader->helper()->SetCanonicalName(i, canonical_name);
   }
 
@@ -1613,7 +1583,7 @@ FunctionNode* FunctionNode::ReadFrom(Reader* reader) {
 
 TypeParameter* TypeParameter::ReadFrom(Reader* reader) {
   TRACE_READ_OFFSET();
-  name_ = Reference::ReadStringFrom(reader);
+  name_index_ = reader->ReadUInt();
   bound_ = DartType::ReadFrom(reader);
   return this;
 }
diff --git a/runtime/vm/kernel_binary.h b/runtime/vm/kernel_binary.h
index 66162d7cb33..08fe8939501 100644
--- a/runtime/vm/kernel_binary.h
+++ b/runtime/vm/kernel_binary.h
@@ -331,7 +331,14 @@ class ReaderHelper {
 class Reader {
  public:
   Reader(const uint8_t* buffer, intptr_t size)
-      : buffer_(buffer), size_(size), offset_(0), string_data_offset_(-1) {}
+      : buffer_(buffer),
+        size_(size),
+        offset_(0),
+        string_table_offset_(-1),
+        string_data_offset_(-1),
+        string_offsets_(NULL) {}
+
+  ~Reader() { delete[] string_offsets_; }
 
   uint32_t ReadUInt32() {
     ASSERT(offset_ + 4 <= size_);
@@ -504,15 +511,25 @@ class Reader {
 
   const uint8_t* buffer() { return buffer_; }
 
+  intptr_t string_table_offset() { return string_table_offset_; }
+  void MarkStringTableOffset() {
+    ASSERT(string_table_offset_ == -1);
+    string_table_offset_ = offset_;
+  }
+
   intptr_t string_data_offset() { return string_data_offset_; }
   void MarkStringDataOffset() {
     ASSERT(string_data_offset_ == -1);
     string_data_offset_ = offset_;
   }
 
-  uint8_t CharacterAt(String* str, intptr_t index) {
-    ASSERT(index < str->size());
-    return buffer_[string_data_offset_ + str->offset() + index];
+  intptr_t StringLength(intptr_t string_index) {
+    return string_offsets_[string_index + 1] - string_offsets_[string_index];
+  }
+
+  uint8_t CharacterAt(intptr_t string_index, intptr_t index) {
+    ASSERT(index < StringLength(string_index));
+    return buffer_[string_data_offset_ + string_offsets_[string_index] + index];
   }
 
  private:
@@ -524,9 +541,17 @@ class Reader {
   TokenPosition min_position_;
   intptr_t current_script_id_;
 
+  // When the binary is deserialized the offset of the start of the string table
+  // (the length) and the offset of the start of the string data are recorded.
+  intptr_t string_table_offset_;
   intptr_t string_data_offset_;
 
+  // The string offsets are decoded to support efficient access to string UTF-8
+  // encodings.
+  intptr_t* string_offsets_;
+
   friend class PositionScope;
+  friend class Program;
 };
 
 
diff --git a/runtime/vm/kernel_binary_flowgraph.cc b/runtime/vm/kernel_binary_flowgraph.cc
index cd7f16b03d4..c23d8be0dc8 100644
--- a/runtime/vm/kernel_binary_flowgraph.cc
+++ b/runtime/vm/kernel_binary_flowgraph.cc
@@ -93,9 +93,10 @@ void StreamingConstantEvaluator::EvaluateStaticGet() {
   }
 }
 
+
 void StreamingConstantEvaluator::EvaluateSymbolLiteral() {
   int str_index = builder_->ReadUInt();
-  const dart::String& symbol_value = builder_->DartSymbol(str_index);
+  const dart::String& symbol_value = H.DartSymbol(str_index);
 
   const dart::Class& symbol_class =
       dart::Class::ZoneHandle(Z, I->object_store()->symbol_class());
@@ -107,12 +108,14 @@ void StreamingConstantEvaluator::EvaluateSymbolLiteral() {
       symbol_class, TypeArguments::Handle(Z), symbol_constructor, symbol_value);
 }
 
+
 void StreamingConstantEvaluator::EvaluateDoubleLiteral() {
   int str_index = builder_->ReadUInt();
-  result_ = dart::Double::New(builder_->DartString(str_index), Heap::kOld);
+  result_ = dart::Double::New(H.DartString(str_index), Heap::kOld);
   result_ = H.Canonicalize(result_);
 }
 
+
 RawObject* StreamingConstantEvaluator::EvaluateConstConstructorCall(
     const dart::Class& type_class,
     const TypeArguments& type_arguments,
@@ -308,26 +311,6 @@ Fragment StreamingFlowGraphBuilder::BuildAt(intptr_t kernel_offset) {
 }
 
 
-intptr_t StreamingFlowGraphBuilder::GetStringOffset(intptr_t index) {
-  if (string_offsets_ == NULL) {
-    intptr_t saved_offset = ReaderOffset();
-    reader_->set_offset(4);  // Skip kMagicProgramFile to the string table.
-    string_offset_count_ = ReadListLength() + 1;
-    string_offsets_ = new intptr_t[string_offset_count_];
-
-    // Build a table of the 0-based string start and end offsets.
-    string_offsets_[0] = 0;
-    for (intptr_t i = 1; i < string_offset_count_; ++i) {
-      string_offsets_[i] = ReadUInt();
-    }
-    // Mark the start of the string data to use for decoding strings.
-    reader_->MarkStringDataOffset();
-    SetOffset(saved_offset);
-  }
-  return string_offsets_[index];
-}
-
-
 CanonicalName* StreamingFlowGraphBuilder::GetCanonicalName(intptr_t index) {
   if (index == 0) return NULL;
   --index;
@@ -395,8 +378,7 @@ CanonicalName* StreamingFlowGraphBuilder::GetCanonicalName(intptr_t index) {
     }
     ASSERT(parent != NULL);
     intptr_t name_index = ReadUInt();
-    String* name = KernelString(name_index);
-    CanonicalName* canonical_name = parent->AddChild(name);
+    CanonicalName* canonical_name = parent->AddChild(name_index);
     canonical_names_[canonical_names_entries_read_] = canonical_name;
   }
 
@@ -457,29 +439,6 @@ ParsedFunction* StreamingFlowGraphBuilder::parsed_function() {
 }
 
 
-dart::String& StreamingFlowGraphBuilder::DartSymbol(intptr_t index) {
-  intptr_t start = GetStringOffset(index);
-  intptr_t end = GetStringOffset(index + 1);
-  return H.DartSymbol(reader_->buffer() + reader_->string_data_offset() + start,
-                      end - start);
-}
-
-
-dart::String& StreamingFlowGraphBuilder::DartString(intptr_t index) {
-  intptr_t start = GetStringOffset(index);
-  intptr_t end = GetStringOffset(index + 1);
-  return H.DartString(reader_->buffer() + reader_->string_data_offset() + start,
-                      end - start);
-}
-
-
-String* StreamingFlowGraphBuilder::KernelString(intptr_t index) {
-  intptr_t start = GetStringOffset(index);
-  intptr_t end = GetStringOffset(index + 1);
-  return new String(start, end - start);
-}
-
-
 Fragment StreamingFlowGraphBuilder::DebugStepCheck(TokenPosition position) {
   return flow_graph_builder_->DebugStepCheck(position);
 }
@@ -603,14 +562,14 @@ Fragment StreamingFlowGraphBuilder::BuildRethrow() {
 
 
 Fragment StreamingFlowGraphBuilder::BuildBigIntLiteral() {
-  const dart::String& value = DartString(ReadUInt());
+  const dart::String& value = H.DartString(ReadUInt());
   return Constant(Integer::ZoneHandle(Z, Integer::New(value, Heap::kOld)));
 }
 
 
 Fragment StreamingFlowGraphBuilder::BuildStringLiteral() {
   intptr_t str_index = ReadUInt();
-  return Constant(DartSymbol(str_index));
+  return Constant(H.DartSymbol(str_index));
 }
 
 
diff --git a/runtime/vm/kernel_binary_flowgraph.h b/runtime/vm/kernel_binary_flowgraph.h
index 3fd552d3faa..d2ce8474055 100644
--- a/runtime/vm/kernel_binary_flowgraph.h
+++ b/runtime/vm/kernel_binary_flowgraph.h
@@ -65,8 +65,6 @@ class StreamingFlowGraphBuilder {
                             flow_graph_builder->zone_,
                             &flow_graph_builder->translation_helper_,
                             &flow_graph_builder->type_translator_),
-        string_offset_count_(0),
-        string_offsets_(NULL),
         canonical_names_(NULL),
         canonical_names_size_(-1),
         canonical_names_entries_read_(0),
@@ -74,7 +72,6 @@ class StreamingFlowGraphBuilder {
 
   virtual ~StreamingFlowGraphBuilder() {
     delete reader_;
-    delete[] string_offsets_;
     // The canonical names themselves are not (yet) deallocated.
     delete[] canonical_names_;
   }
@@ -82,7 +79,6 @@ class StreamingFlowGraphBuilder {
   Fragment BuildAt(intptr_t kernel_offset);
 
  private:
-  intptr_t GetStringOffset(intptr_t index);
   CanonicalName* GetCanonicalName(intptr_t index);
 
   intptr_t ReaderOffset();
@@ -97,10 +93,6 @@ class StreamingFlowGraphBuilder {
   ScopeBuildingResult* scopes();
   ParsedFunction* parsed_function();
 
-  dart::String& DartSymbol(intptr_t str_index);
-  dart::String& DartString(intptr_t str_index);
-  String* KernelString(intptr_t str_index);
-
   Fragment DebugStepCheck(TokenPosition position);
   Fragment LoadLocal(LocalVariable* variable);
   Fragment PushArgument();
@@ -132,19 +124,6 @@ class StreamingFlowGraphBuilder {
   kernel::Reader* reader_;
   StreamingConstantEvaluator constant_evaluator_;
 
-  // We build a table that gives us the start and end offsets of all the strings
-  // in the binary.
-  //
-  // The number of string offsets.  Note that this is one more than the number
-  // of strings in the binary.
-  intptr_t string_offset_count_;
-
-  // An array of offsets of size string_table_size_ + 1, in order to include the
-  // end offset of the last string.  The string with index N consists of the
-  // UTF-8 encoded bytes stretching from string_table_offsets_[N] (enclusive) to
-  // string_table_offsets_[N+1] (exclusive).
-  intptr_t* string_offsets_;
-
   CanonicalName** canonical_names_;
   intptr_t canonical_names_size_;
   intptr_t canonical_names_entries_read_;
diff --git a/runtime/vm/kernel_reader.cc b/runtime/vm/kernel_reader.cc
index d9c9d209125..0879f95ed2e 100644
--- a/runtime/vm/kernel_reader.cc
+++ b/runtime/vm/kernel_reader.cc
@@ -7,6 +7,7 @@
 #include <string.h>
 
 #include "vm/dart_api_impl.h"
+#include "vm/kernel_binary.h"
 #include "vm/longjump.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
@@ -118,24 +119,32 @@ KernelReader::KernelReader(Program* program)
   intptr_t source_file_count = program->source_table().size();
   scripts_ = Array::New(source_file_count, Heap::kOld);
 
-  // Copy the Kernel strings out of the binary and into the VM's heap.  The size
-  // of the string data can be computed from the offset and size of the last
-  // string.  This relies on the strings occurring in order in the program's
-  // string table.
-  List<String>& strings = program->string_table().strings();
-  String* last_string = strings[strings.length() - 1];
-  intptr_t size = last_string->offset() + last_string->size();
-  TypedData& data = TypedData::Handle(
-      Z, TypedData::New(kTypedDataUint8ArrayCid, size, Heap::kOld));
-  ASSERT(program->string_data_offset() >= 0);
   // We need at least one library to get access to the binary.
   ASSERT(program->libraries().length() > 0);
+  Library* library = program->libraries()[0];
+  Reader reader(library->kernel_data(), library->kernel_data_size());
+
+  // Copy the Kernel string offsets out of the binary and into the VM's heap.
+  ASSERT(program->string_table_offset() >= 0);
+  reader.set_offset(program->string_table_offset());
+  intptr_t count = reader.ReadUInt() + 1;
+  TypedData& offsets = TypedData::Handle(
+      Z, TypedData::New(kTypedDataUint32ArrayCid, count, Heap::kOld));
+  offsets.SetUint32(0, 0);
+  intptr_t end_offset = 0;
+  for (intptr_t i = 1; i < count; ++i) {
+    end_offset = reader.ReadUInt();
+    offsets.SetUint32(i << 2, end_offset);
+  }
+
+  // Copy the string data out of the binary and into the VM's heap.
+  TypedData& data = TypedData::Handle(
+      Z, TypedData::New(kTypedDataUint8ArrayCid, end_offset, Heap::kOld));
   {
     NoSafepointScope no_safepoint;
-    memmove(data.DataAddr(0), program->libraries()[0]->kernel_data() +
-                                  program->string_data_offset(),
-            size);
+    memmove(data.DataAddr(0), reader.buffer() + reader.offset(), end_offset);
   }
+  H.SetStringOffsets(offsets);
   H.SetStringData(data);
 }
 
@@ -487,12 +496,12 @@ void KernelReader::ReadProcedure(const dart::Library& library,
           ConstructorInvocation::Cast(annotation);
       CanonicalName* annotation_class = H.EnclosingName(invocation->target());
       ASSERT(H.IsClass(annotation_class));
-      String* class_name = annotation_class->name();
+      intptr_t class_name_index = annotation_class->name();
       // Just compare by name, do not generate the annotation class.
-      if (!H.StringEquals(class_name, "ExternalName")) continue;
+      if (!H.StringEquals(class_name_index, "ExternalName")) continue;
       ASSERT(H.IsLibrary(annotation_class->parent()));
-      String* library_name = annotation_class->parent()->name();
-      if (!H.StringEquals(library_name, "dart:_internal")) continue;
+      intptr_t library_name_index = annotation_class->parent()->name();
+      if (!H.StringEquals(library_name_index, "dart:_internal")) continue;
 
       is_external = false;
       ASSERT(invocation->arguments()->positional().length() == 1 &&
@@ -607,7 +616,7 @@ static RawArray* AsSortedDuplicateFreeArray(
   }
 }
 
-Script& KernelReader::ScriptAt(intptr_t index, String* import_uri) {
+Script& KernelReader::ScriptAt(intptr_t index, intptr_t import_uri) {
   Script& script = Script::ZoneHandle(Z);
   script ^= scripts_.At(index);
   if (script.IsNull()) {
@@ -616,14 +625,15 @@ Script& KernelReader::ScriptAt(intptr_t index, String* import_uri) {
     intptr_t uri_size = program_->source_table().UriSizeFor(index);
     dart::String& uri_string = H.DartString(uri_buffer, uri_size, Heap::kOld);
     dart::String& import_uri_string =
-        import_uri == NULL ? uri_string : H.DartString(import_uri, Heap::kOld);
+        import_uri == -1 ? uri_string : H.DartString(import_uri, Heap::kOld);
     uint8_t* source_buffer = program_->source_table().SourceCodeFor(index);
     intptr_t source_size = program_->source_table().SourceCodeSizeFor(index);
     dart::String& source_code =
         H.DartString(source_buffer, source_size, Heap::kOld);
     script = Script::New(import_uri_string, uri_string, source_code,
                          RawScript::kKernelTag);
-    script.set_kernel_strings(H.string_data());
+    script.set_kernel_string_offsets(H.string_offsets());
+    script.set_kernel_string_data(H.string_data());
     scripts_.SetAt(index, script);
 
     // Create line_starts array for the script.
diff --git a/runtime/vm/kernel_reader.h b/runtime/vm/kernel_reader.h
index 7e3399b6eac..4b54010d2cb 100644
--- a/runtime/vm/kernel_reader.h
+++ b/runtime/vm/kernel_reader.h
@@ -67,11 +67,11 @@ class KernelReader {
 
   void ReadLibrary(Library* kernel_library);
 
-  const dart::String& DartSymbol(String* str) {
-    return translation_helper_.DartSymbol(str);
+  const dart::String& DartSymbol(intptr_t string_index) {
+    return translation_helper_.DartSymbol(string_index);
   }
 
-  uint8_t CharacterAt(String* str, intptr_t index);
+  uint8_t CharacterAt(intptr_t string_index, intptr_t index);
 
  private:
   friend class BuildingTranslationHelper;
@@ -92,7 +92,7 @@ class KernelReader {
   // Otherwise return klass.
   const Object& ClassForScriptAt(const dart::Class& klass,
                                  intptr_t source_uri_index);
-  Script& ScriptAt(intptr_t source_uri_index, String* import_uri = NULL);
+  Script& ScriptAt(intptr_t source_uri_index, intptr_t import_uri = -1);
 
   void GenerateFieldAccessors(const dart::Class& klass,
                               const dart::Field& field,
diff --git a/runtime/vm/kernel_to_il.cc b/runtime/vm/kernel_to_il.cc
index 9f2d4601307..001127cb58e 100644
--- a/runtime/vm/kernel_to_il.cc
+++ b/runtime/vm/kernel_to_il.cc
@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 #include <set>
-#include <string>
 
 #include "vm/kernel_to_il.h"
 
@@ -71,7 +70,8 @@ ScopeBuilder::ScopeBuilder(ParsedFunction* parsed_function, TreeNode* node)
       name_index_(0),
       needs_expr_temp_(false) {
   Script& script = Script::Handle(Z, parsed_function->function().script());
-  H.SetStringData(TypedData::Handle(Z, script.kernel_strings()));
+  H.SetStringOffsets(TypedData::Handle(Z, script.kernel_string_offsets()));
+  H.SetStringData(TypedData::Handle(Z, script.kernel_string_data()));
 }
 
 
@@ -261,7 +261,7 @@ void ScopeBuilder::AddVariable(VariableDeclaration* declaration) {
   // In case `declaration->IsConst()` the flow graph building will take care of
   // evaluating the constant and setting it via
   // `declaration->SetConstantValue()`.
-  const dart::String& name = declaration->name()->is_empty()
+  const dart::String& name = (H.StringSize(declaration->name()) == 0)
                                  ? GenerateName(":var", name_index_++)
                                  : H.DartSymbol(declaration->name());
   LocalVariable* variable =
@@ -1043,7 +1043,14 @@ TranslationHelper::TranslationHelper(dart::Thread* thread)
       zone_(thread->zone()),
       isolate_(thread->isolate()),
       allocation_space_(thread->IsMutatorThread() ? Heap::kNew : Heap::kOld),
-      string_data_(TypedData::Handle(zone_)) {}
+      string_offsets_(TypedData::Handle(Z)),
+      string_data_(TypedData::Handle(Z)) {}
+
+
+void TranslationHelper::SetStringOffsets(const TypedData& string_offsets) {
+  ASSERT(string_offsets_.IsNull());
+  string_offsets_ = string_offsets.raw();
+}
 
 
 void TranslationHelper::SetStringData(const TypedData& string_data) {
@@ -1052,29 +1059,42 @@ void TranslationHelper::SetStringData(const TypedData& string_data) {
 }
 
 
-uint8_t TranslationHelper::CharacterAt(String* string, intptr_t index) {
-  ASSERT(index < string->size());
-  return string_data_.GetUint8(string->offset() + index);
+intptr_t TranslationHelper::StringOffset(intptr_t string_index) const {
+  return string_offsets_.GetUint32(string_index << 2);
 }
 
 
-bool TranslationHelper::StringEquals(String* string, const char* other) {
+intptr_t TranslationHelper::StringSize(intptr_t string_index) const {
+  return StringOffset(string_index + 1) - StringOffset(string_index);
+}
+
+
+uint8_t TranslationHelper::CharacterAt(intptr_t string_index, intptr_t index) {
+  ASSERT(index < StringSize(string_index));
+  return string_data_.GetUint8(StringOffset(string_index) + index);
+}
+
+
+bool TranslationHelper::StringEquals(intptr_t string_index, const char* other) {
   NoSafepointScope no_safepoint;
   intptr_t length = strlen(other);
-  return (length == string->size()) &&
-         memcmp(string_data_.DataAddr(string->offset()), other, length) == 0;
+  return (length == StringSize(string_index)) &&
+         (memcmp(string_data_.DataAddr(StringOffset(string_index)), other,
+                 length) == 0);
 }
 
 
 bool TranslationHelper::IsAdministrative(CanonicalName* name) {
   // Administrative names start with '@'.
-  return (name->name()->size() > 0) && (CharacterAt(name->name(), 0) == '@');
+  return (StringSize(name->name()) > 0) &&
+         (CharacterAt(name->name(), 0) == '@');
 }
 
 
 bool TranslationHelper::IsPrivate(CanonicalName* name) {
   // Private names start with '_'.
-  return (name->name()->size() > 0) && (CharacterAt(name->name(), 0) == '_');
+  return (StringSize(name->name()) > 0) &&
+         (CharacterAt(name->name(), 0) == '_');
 }
 
 
@@ -1228,13 +1248,13 @@ const dart::String& TranslationHelper::DartString(const char* content,
 }
 
 
-dart::String& TranslationHelper::DartString(String* content,
+dart::String& TranslationHelper::DartString(intptr_t string_index,
                                             Heap::Space space) {
-  intptr_t length = content->size();
+  intptr_t length = StringSize(string_index);
   uint8_t* buffer = Z->Alloc<uint8_t>(length);
   {
     NoSafepointScope no_safepoint;
-    memmove(buffer, string_data_.DataAddr(content->offset()), length);
+    memmove(buffer, string_data_.DataAddr(StringOffset(string_index)), length);
   }
   return dart::String::ZoneHandle(
       Z, dart::String::FromUTF8(buffer, length, space));
@@ -1254,12 +1274,12 @@ const dart::String& TranslationHelper::DartSymbol(const char* content) const {
 }
 
 
-dart::String& TranslationHelper::DartSymbol(String* content) const {
-  intptr_t length = content->size();
+dart::String& TranslationHelper::DartSymbol(intptr_t string_index) const {
+  intptr_t length = StringSize(string_index);
   uint8_t* buffer = Z->Alloc<uint8_t>(length);
   {
     NoSafepointScope no_safepoint;
-    memmove(buffer, string_data_.DataAddr(content->offset()), length);
+    memmove(buffer, string_data_.DataAddr(StringOffset(string_index)), length);
   }
   return dart::String::ZoneHandle(
       Z, dart::Symbols::FromUTF8(thread_, buffer, length));
@@ -1307,12 +1327,12 @@ const dart::String& TranslationHelper::DartSetterName(CanonicalName* setter) {
 
 
 const dart::String& TranslationHelper::DartSetterName(Name* setter_name) {
-  return DartSetterName(setter_name->library(), setter_name->string());
+  return DartSetterName(setter_name->library(), setter_name->string_index());
 }
 
 
 const dart::String& TranslationHelper::DartSetterName(CanonicalName* parent,
-                                                      String* setter) {
+                                                      intptr_t setter) {
   // The names flowing into [setter] are coming from the Kernel file:
   //   * user-defined setters: `fieldname=`
   //   * property-set expressions:  `fieldname`
@@ -1321,19 +1341,18 @@ const dart::String& TranslationHelper::DartSetterName(CanonicalName* parent,
   //
   // => In order to be consistent, we remove the `=` always and adopt the VM
   //    conventions.
-  ASSERT(setter->size() > 0);
-  intptr_t skip = 0;
-  if (CharacterAt(setter, setter->size() - 1) == '=') {
-    skip = 1;
+  intptr_t size = StringSize(setter);
+  ASSERT(size > 0);
+  if (CharacterAt(setter, size - 1) == '=') {
+    --size;
   }
-  intptr_t length = setter->size() - skip;
-  uint8_t* buffer = Z->Alloc<uint8_t>(length);
+  uint8_t* buffer = Z->Alloc<uint8_t>(size);
   {
     NoSafepointScope no_safepoint;
-    memmove(buffer, string_data_.DataAddr(setter->offset()), length);
+    memmove(buffer, string_data_.DataAddr(StringOffset(setter)), size);
   }
   dart::String& name = dart::String::ZoneHandle(
-      Z, dart::String::FromUTF8(buffer, length, allocation_space_));
+      Z, dart::String::FromUTF8(buffer, size, allocation_space_));
   ManglePrivateName(parent, &name, false);
   name = dart::Field::SetterSymbol(name);
   return name;
@@ -1346,12 +1365,12 @@ const dart::String& TranslationHelper::DartGetterName(CanonicalName* getter) {
 
 
 const dart::String& TranslationHelper::DartGetterName(Name* getter_name) {
-  return DartGetterName(getter_name->library(), getter_name->string());
+  return DartGetterName(getter_name->library(), getter_name->string_index());
 }
 
 
 const dart::String& TranslationHelper::DartGetterName(CanonicalName* parent,
-                                                      String* getter) {
+                                                      intptr_t getter) {
   dart::String& name = DartString(getter);
   ManglePrivateName(parent, &name, false);
   name = dart::Field::GetterSymbol(name);
@@ -1360,7 +1379,7 @@ const dart::String& TranslationHelper::DartGetterName(CanonicalName* parent,
 
 
 const dart::String& TranslationHelper::DartFieldName(Name* kernel_name) {
-  dart::String& name = DartString(kernel_name->string());
+  dart::String& name = DartString(kernel_name->string_index());
   return ManglePrivateName(kernel_name->library(), &name);
 }
 
@@ -1380,12 +1399,12 @@ const dart::String& TranslationHelper::DartMethodName(CanonicalName* method) {
 
 
 const dart::String& TranslationHelper::DartMethodName(Name* method_name) {
-  return DartMethodName(method_name->library(), method_name->string());
+  return DartMethodName(method_name->library(), method_name->string_index());
 }
 
 
 const dart::String& TranslationHelper::DartMethodName(CanonicalName* parent,
-                                                      String* method) {
+                                                      intptr_t method) {
   dart::String& name = DartString(method);
   return ManglePrivateName(parent, &name);
 }
@@ -2057,10 +2076,8 @@ void ConstantEvaluator::VisitNot(Not* node) {
 
 
 void ConstantEvaluator::VisitPropertyGet(PropertyGet* node) {
-  const intptr_t kLengthLen = sizeof("length") - 1;
-
-  String* string = node->name()->string();
-  if ((string->size() == kLengthLen) && H.StringEquals(string, "length")) {
+  intptr_t string_index = node->name()->string_index();
+  if (H.StringEquals(string_index, "length")) {
     node->receiver()->AcceptExpressionVisitor(this);
     if (result_.IsString()) {
       const dart::String& str =
@@ -2187,7 +2204,8 @@ FlowGraphBuilder::FlowGraphBuilder(
       constant_evaluator_(this, zone_, &translation_helper_, &type_translator_),
       streaming_flow_graph_builder_(NULL) {
   Script& script = Script::Handle(Z, parsed_function->function().script());
-  H.SetStringData(TypedData::Handle(Z, script.kernel_strings()));
+  H.SetStringOffsets(TypedData::Handle(Z, script.kernel_string_offsets()));
+  H.SetStringData(TypedData::Handle(Z, script.kernel_string_data()));
 }
 
 
@@ -4682,13 +4700,13 @@ void DartTypeTranslator::VisitFunctionType(FunctionType* node) {
     parameter_names.SetAt(pos, H.DartSymbol("noname"));
   }
   for (intptr_t i = 0; i < named_count; i++, pos++) {
-    Tuple<String, DartType>* tuple = node->named_parameters()[i];
-    tuple->second()->AcceptDartTypeVisitor(this);
+    NamedParameter* parameter = node->named_parameters()[i];
+    parameter->type()->AcceptDartTypeVisitor(this);
     if (result_.IsMalformed()) {
       result_ = AbstractType::dynamic_type().raw();
     }
     parameter_types.SetAt(pos, result_);
-    parameter_names.SetAt(pos, H.DartSymbol(tuple->first()));
+    parameter_names.SetAt(pos, H.DartSymbol(parameter->name()));
   }
 
   Type& signature_type =
@@ -6733,7 +6751,9 @@ RawObject* EvaluateMetadata(const dart::Field& metadata_field) {
 
     TranslationHelper helper(thread);
     Script& script = Script::Handle(Z, metadata_field.Script());
-    helper.SetStringData(TypedData::Handle(Z, script.kernel_strings()));
+    helper.SetStringOffsets(
+        TypedData::Handle(Z, script.kernel_string_offsets()));
+    helper.SetStringData(TypedData::Handle(Z, script.kernel_string_data()));
     DartTypeTranslator type_translator(&helper, NULL, true);
     ConstantEvaluator constant_evaluator(/* flow_graph_builder = */ NULL, Z,
                                          &helper, &type_translator);
diff --git a/runtime/vm/kernel_to_il.h b/runtime/vm/kernel_to_il.h
index 148ecd6e1fc..503890662f4 100644
--- a/runtime/vm/kernel_to_il.h
+++ b/runtime/vm/kernel_to_il.h
@@ -281,10 +281,16 @@ class TranslationHelper {
   Heap::Space allocation_space() { return allocation_space_; }
 
   // Access to strings.
+  const TypedData& string_offsets() { return string_offsets_; }
+  void SetStringOffsets(const TypedData& string_data);
+
   const TypedData& string_data() { return string_data_; }
   void SetStringData(const TypedData& string_data);
-  uint8_t CharacterAt(String* str, intptr_t index);
-  bool StringEquals(String* str, const char* other);
+
+  intptr_t StringOffset(intptr_t string_index) const;
+  intptr_t StringSize(intptr_t string_index) const;
+  uint8_t CharacterAt(intptr_t string_index, intptr_t index);
+  bool StringEquals(intptr_t string_index, const char* other);
 
   // Predicates on CanonicalNames.
   bool IsAdministrative(CanonicalName* name);
@@ -312,10 +318,10 @@ class TranslationHelper {
   }
   const dart::String& DartString(const char* content, Heap::Space space);
 
-  dart::String& DartString(String* content) {
-    return DartString(content, allocation_space_);
+  dart::String& DartString(intptr_t string_index) {
+    return DartString(string_index, allocation_space_);
   }
-  dart::String& DartString(String* content, Heap::Space space);
+  dart::String& DartString(intptr_t string_index, Heap::Space space);
 
   dart::String& DartString(const uint8_t* utf8_array, intptr_t len) {
     return DartString(utf8_array, len, allocation_space_);
@@ -325,7 +331,7 @@ class TranslationHelper {
                            Heap::Space space);
 
   const dart::String& DartSymbol(const char* content) const;
-  dart::String& DartSymbol(String* content) const;
+  dart::String& DartSymbol(intptr_t string_index) const;
   dart::String& DartSymbol(const uint8_t* utf8_array, intptr_t len) const;
 
   const dart::String& DartClassName(CanonicalName* kernel_class);
@@ -378,15 +384,16 @@ class TranslationHelper {
                                   dart::String* name_to_modify,
                                   bool symbolize = true);
 
-  const dart::String& DartSetterName(CanonicalName* parent, String* setter);
-  const dart::String& DartGetterName(CanonicalName* parent, String* getter);
-  const dart::String& DartMethodName(CanonicalName* parent, String* method);
+  const dart::String& DartSetterName(CanonicalName* parent, intptr_t setter);
+  const dart::String& DartGetterName(CanonicalName* parent, intptr_t getter);
+  const dart::String& DartMethodName(CanonicalName* parent, intptr_t method);
 
   Thread* thread_;
   Zone* zone_;
   Isolate* isolate_;
   Heap::Space allocation_space_;
 
+  TypedData& string_offsets_;
   TypedData& string_data_;
 };
 
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 9420ca91804..39531c3dbc5 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -9098,8 +9098,13 @@ void Script::set_compile_time_constants(const Array& value) const {
 }
 
 
-void Script::set_kernel_strings(const TypedData& strings) const {
-  StorePointer(&raw_ptr()->kernel_strings_, strings.raw());
+void Script::set_kernel_string_offsets(const TypedData& offsets) const {
+  StorePointer(&raw_ptr()->kernel_string_offsets_, offsets.raw());
+}
+
+
+void Script::set_kernel_string_data(const TypedData& data) const {
+  StorePointer(&raw_ptr()->kernel_string_data_, data.raw());
 }
 
 
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 2848def5f35..bbba1cd1e87 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -3591,8 +3591,15 @@ class Script : public Object {
   }
   void set_compile_time_constants(const Array& value) const;
 
-  RawTypedData* kernel_strings() const { return raw_ptr()->kernel_strings_; }
-  void set_kernel_strings(const TypedData& strings) const;
+  RawTypedData* kernel_string_offsets() const {
+    return raw_ptr()->kernel_string_offsets_;
+  }
+  void set_kernel_string_offsets(const TypedData& offsets) const;
+
+  RawTypedData* kernel_string_data() const {
+    return raw_ptr()->kernel_string_data_;
+  }
+  void set_kernel_string_data(const TypedData& data) const;
 
   RawTokenStream* tokens() const {
     ASSERT(kind() != RawScript::kKernelTag);
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index de6956610cd..a5f2ca7523d 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -1026,7 +1026,8 @@ class RawScript : public RawObject {
   RawArray* line_starts_;
   RawArray* debug_positions_;
   RawArray* yield_positions_;
-  RawTypedData* kernel_strings_;
+  RawTypedData* kernel_string_offsets_;
+  RawTypedData* kernel_string_data_;
   RawTokenStream* tokens_;
   RawString* source_;
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->source_); }