diff --git a/sfntly/table/core/cmap_table.cc b/sfntly/table/core/cmap_table.cc
index dd43996..bbe4497 100644
--- a/sfntly/table/core/cmap_table.cc
+++ b/sfntly/table/core/cmap_table.cc
@@ -14,24 +14,93 @@
  * limitations under the License.
  */
 
-// TODO(arthurhsu): IMPLEMENT: not really used and tested, need cleanup
-
-#include <cstdlib>
-
 #include "sfntly/table/core/cmap_table.h"
-#include "sfntly/table/core/name_table.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <utility>
+
 #include "sfntly/font.h"
+#include "sfntly/math/font_math.h"
 #include "sfntly/port/endian.h"
+#include "sfntly/port/exception_type.h"
+#include "sfntly/table/core/name_table.h"
 
 namespace sfntly {
 
 const int32_t CMapTable::NOTDEF = 0;
 
+CMapTable::CMapId CMapTable::WINDOWS_BMP = {
+  PlatformId::kWindows,
+  WindowsEncodingId::kUnicodeUCS2
+};
+CMapTable::CMapId CMapTable::WINDOWS_UCS4 = {
+  PlatformId::kWindows,
+  WindowsEncodingId::kUnicodeUCS4
+};
+CMapTable::CMapId CMapTable::MAC_ROMAN = {
+  PlatformId::kWindows,
+  MacintoshEncodingId::kRoman
+};
+
 /******************************************************************************
  * CMapTable class
  ******************************************************************************/
+CMapTable::CMapTable(Header* header, ReadableFontData* data)
+  : SubTableContainerTable(header, data) {
+}
+
 CMapTable::~CMapTable() {}
 
+CALLER_ATTACH CMapTable::CMap* CMapTable::GetCMap(const int32_t index) {
+  if (index < 0 || index > NumCMaps()) {
+#ifndef SFNTLY_NO_EXCEPTION
+    throw IndexOutOfBoundException("Requested CMap index is out of bounds.");
+#else
+    return NULL;
+#endif
+  }
+  int32_t platform_id = PlatformId(index);
+  int32_t encoding_id = EncodingId(index);
+  CMapId cmap_id = NewCMapId(platform_id, encoding_id);
+  int32_t offset_ = Offset(index);
+  Ptr<FontDataTable::Builder> cmap_builder =
+      (CMap::Builder::GetBuilder(data_, offset_, cmap_id));
+  if (!cmap_builder) {
+#ifndef SFNTLY_NO_EXCEPTION
+    throw NoSuchElementException("Cannot find builder for requested CMap.");
+#else
+    return NULL;
+#endif
+  }
+  return reinterpret_cast<CMapTable::CMap*>(cmap_builder->Build());
+}
+
+CALLER_ATTACH CMapTable::CMap* CMapTable::GetCMap(const int32_t platform_id,
+                                                  const int32_t encoding_id) {
+  return GetCMap(NewCMapId(platform_id, encoding_id));
+}
+
+CALLER_ATTACH CMapTable::CMap*
+CMapTable::GetCMap(const CMapTable::CMapId cmap_id) {
+  CMapIdFilter* id_filter = new CMapIdFilter(cmap_id);
+  CMapIterator cmap_iterator(this, id_filter);
+  // There can only be one cmap with a particular CMapId
+  if (cmap_iterator.HasNext()) {
+    Ptr<CMapTable::CMap> cmap;
+    cmap.Attach(cmap_iterator.Next());
+    delete id_filter;
+    return cmap.Detach();
+  }
+  delete id_filter;
+#ifndef SFNTLY_NO_EXCEPTION
+  throw NoSuchElementException();
+#else
+  return NULL;
+#endif
+}
+
 int32_t CMapTable::Version() {
   return data_->ReadUShort(Offset::kVersion);
 }
@@ -41,7 +110,7 @@
 }
 
 CMapTable::CMapId CMapTable::GetCMapId(int32_t index) {
-  return CMapId(PlatformId(index), EncodingId(index));
+  return NewCMapId(PlatformId(index), EncodingId(index));
 }
 
 int32_t CMapTable::PlatformId(int32_t index) {
@@ -59,53 +128,101 @@
                                OffsetForEncodingRecord(index));
 }
 
-CMapTable::CMapTable(Header* header, ReadableFontData* data)
-    : SubTableContainerTable(header, data) {
-}
-
 int32_t CMapTable::OffsetForEncodingRecord(int32_t index) {
   return Offset::kEncodingRecordStart + index * Offset::kEncodingRecordSize;
 }
 
+CMapTable::CMapId CMapTable::NewCMapId(int32_t platform_id,
+                                       int32_t encoding_id) {
+  CMapId result;
+  result.platform_id = platform_id;
+  result.encoding_id = encoding_id;
+  return result;
+}
+
+CMapTable::CMapId CMapTable::NewCMapId(const CMapId& obj) {
+  CMapId result;
+  result.platform_id = obj.platform_id;
+  result.encoding_id = obj.encoding_id;
+  return result;
+}
+
+/******************************************************************************
+ * CMapTable::CMapIterator class
+ ******************************************************************************/
+CMapTable::CMapIterator::CMapIterator(CMapTable* table,
+                                      const CMapFilter* filter)
+    : table_index_(0), filter_(filter), table_(table) {
+}
+
+bool CMapTable::CMapIterator::HasNext() {
+  if (!filter_) {
+    if (table_index_ < table_->NumCMaps()) {
+      return true;
+    }
+    return false;
+  }
+
+  for (; table_index_ < table_->NumCMaps(); ++table_index_) {
+    if (filter_->accept(table_->GetCMapId(table_index_))) {
+      return true;
+    }
+  }
+  return false;
+}
+
+CALLER_ATTACH CMapTable::CMap* CMapTable::CMapIterator::Next() {
+  if (!HasNext()) {
+#ifndef SFNTLY_NO_EXCEPTION
+    throw NoSuchElementException();
+#else
+    return NULL;
+#endif
+  }
+  CMapPtr next_cmap;
+  next_cmap.Attach(table_->GetCMap(table_index_++));
+  if (next_cmap == NULL) {
+#ifndef SFNTLY_NO_EXCEPTION
+    throw NoSuchElementException("Error during the creation of the CMap");
+#else
+    return NULL;
+#endif
+  }
+  return next_cmap.Detach();
+}
+
 /******************************************************************************
  * CMapTable::CMapId class
  ******************************************************************************/
-CMapTable::CMapId::CMapId(int32_t platform_id, int32_t encoding_id)
-    : platform_id_(platform_id), encoding_id_(encoding_id) {
-}
-
-CMapTable::CMapId::CMapId(const CMapId& obj)
-    : platform_id_(obj.platform_id_), encoding_id_(obj.encoding_id_) {
-}
-
-bool CMapTable::CMapId::operator==(const CMapTable::CMapId& obj) {
-  return obj.platform_id_ == platform_id_ && obj.encoding_id_ == encoding_id_;
-}
-
-const CMapTable::CMapId& CMapTable::CMapId::operator=(
-    const CMapTable::CMapId& obj) {
-  platform_id_ = obj.platform_id_;
-  encoding_id_ = obj.encoding_id_;
-  return *this;
-}
-
-int CMapTable::CMapId::HashCode() const {
-  return platform_id_ << 8 | encoding_id_;
-}
-
-CMapTable::CMapId WINDOWS_BMP(PlatformId::kWindows,
-                              WindowsEncodingId::kUnicodeUCS2);
-CMapTable::CMapId WINDOWS_UCS4(PlatformId::kWindows,
-                               WindowsEncodingId::kUnicodeUCS4);
-CMapTable::CMapId MAC_ROMAN(PlatformId::kWindows, MacintoshEncodingId::kRoman);
 
 /******************************************************************************
  * CMapTable::CMapIdComparator class
  ******************************************************************************/
 
 bool CMapTable::CMapIdComparator::operator()(const CMapId& lhs,
-                                             const CMapId& rhs) {
-  return lhs.HashCode() > rhs.HashCode();
+                                             const CMapId& rhs) const {
+  return ((lhs.platform_id << 8 | lhs.encoding_id) >
+      (rhs.platform_id << 8 | rhs.encoding_id));
+}
+
+/******************************************************************************
+ * CMapTable::CMapIdFilter class
+ ******************************************************************************/
+CMapTable::CMapIdFilter::CMapIdFilter(const CMapId wanted_id)
+    : wanted_id_(wanted_id),
+      comparator_(NULL) {
+}
+
+CMapTable::CMapIdFilter::CMapIdFilter(const CMapId wanted_id,
+                                      const CMapIdComparator* comparator)
+    : wanted_id_(wanted_id),
+      comparator_(comparator) {
+}
+
+bool CMapTable::CMapIdFilter::accept(const CMapId& cmap_id) const {
+  if (!comparator_)
+    return wanted_id_ == cmap_id;
+  return (*comparator_)(wanted_id_, cmap_id);
 }
 
 /******************************************************************************
@@ -126,20 +243,59 @@
 }
 
 CALLER_ATTACH CMapTable::CMap::Builder*
-    CMapTable::CMap::Builder::GetBuilder(ReadableFontData* data,
-                                         int32_t offset,
+    CMapTable::CMap::Builder::GetBuilder(ReadableFontData* data, int32_t offset,
                                          const CMapId& cmap_id) {
   // NOT IMPLEMENTED: Java enum value validation
   int32_t format = data->ReadUShort(offset);
   CMapBuilderPtr builder;
   switch (format) {
     case CMapFormat::kFormat0:
-      builder = new CMapFormat0::Builder(data, offset, cmap_id);
+      builder.Attach(CMapFormat0::Builder::NewInstance(data, offset, cmap_id));
       break;
     case CMapFormat::kFormat2:
-      builder = new CMapFormat0::Builder(data, offset, cmap_id);
+#if defined (SFNTLY_DEBUG_CMAP)
+      fprintf(stderr, "Requesting Format2 builder, but it's unsupported; "
+              "returning NULL\n");
+#endif
+      break;
+    case CMapFormat::kFormat4:
+#if defined (SFNTLY_DEBUG_CMAP)
+      fprintf(stderr, "Requesting Format4 builder, but it's unsupported; "
+              "returning NULL\n");
+#endif
       break;
     default:
+#ifdef SFNTLY_DEBUG_CMAP
+      fprintf(stderr, "Unknown builder format requested\n");
+#endif
+      break;
+  }
+  return builder.Detach();
+}
+
+CALLER_ATTACH CMapTable::CMap::Builder*
+CMapTable::CMap::Builder::GetBuilder(int32_t format, const CMapId& cmap_id) {
+  Ptr<CMapTable::CMap::Builder> builder;
+  switch (format) {
+    case CMapFormat::kFormat0:
+      builder.Attach(CMapFormat0::Builder::NewInstance(cmap_id));
+      break;
+    case CMapFormat::kFormat2:
+#if defined (SFNTLY_DEBUG_CMAP)
+      fprintf(stderr, "Requesting Format2 builder, but it's unsupported; "
+              "returning NULL\n");
+#endif
+      break;
+    case CMapFormat::kFormat4:
+#if defined (SFNTLY_DEBUG_CMAP)
+      fprintf(stderr, "Requesting Format4 builder, but it's unsupported; "
+              "returning NULL\n");
+#endif
+      break;
+    default:
+#ifdef SFNTLY_DEBUG_CMAP
+      fprintf(stderr, "Unknown builder format requested\n");
+#endif
       break;
   }
   return builder.Detach();
@@ -150,7 +306,8 @@
                                   const CMapId& cmap_id)
     : SubTable::Builder(data),
       format_(format),
-      cmap_id_(cmap_id) {
+      cmap_id_(cmap_id),
+      language_(0) {
 }
 
 CMapTable::CMap::Builder::Builder(WritableFontData* data,
@@ -158,7 +315,8 @@
                                   const CMapId& cmap_id)
     : SubTable::Builder(data),
       format_(format),
-      cmap_id_(cmap_id) {
+      cmap_id_(cmap_id),
+      language_(0) {
 }
 
 int32_t CMapTable::CMap::Builder::SubSerialize(WritableFontData* new_data) {
@@ -170,7 +328,10 @@
 }
 
 int32_t CMapTable::CMap::Builder::SubDataSizeToSerialize() {
-  return InternalReadData()->Length();
+  ReadableFontDataPtr read_data = InternalReadData();
+  if (!read_data)
+    return 0;
+  return read_data->Length();
 }
 
 void CMapTable::CMap::Builder::SubDataSet() {
@@ -191,7 +352,7 @@
   if (character < 0 || character > 255) {
     return CMapTable::NOTDEF;
   }
-  return data_->ReadByte(character + Offset::kFormat0GlyphIdArray);
+  return data_->ReadUByte(character + Offset::kFormat0GlyphIdArray);
 }
 
 CMapTable::CMapFormat0::CMapFormat0(ReadableFontData* data,
@@ -199,29 +360,94 @@
     : CMap(data, CMapFormat::kFormat0, cmap_id) {
 }
 
+void
+CMapTable::CMapFormat0::Iterator(CMapTable::CMap::CharacterIterator* output) {
+  output = new CMapTable::CMapFormat0::CharacterIterator(0, 0xff);
+}
+
+
+/******************************************************************************
+ * CMapTable::CMapFormat0::CharacterIterator
+ ******************************************************************************/
+CMapTable::CMapFormat0::CharacterIterator::CharacterIterator(int32_t start,
+                                                             int32_t end)
+    : character_(start),
+    max_character_(end) {
+}
+
+CMapTable::CMapFormat0::CharacterIterator::~CharacterIterator() {}
+
+bool CMapTable::CMapFormat0::CharacterIterator::HasNext() {
+  return character_ < max_character_;
+}
+
+int32_t CMapTable::CMapFormat0::CharacterIterator::Next() {
+  if (HasNext())
+    return character_++;
+#ifndef SFNTLY_NO_EXCEPTION
+  throw NoSuchElementException("No more characters to iterate.");
+#endif
+  return -1;
+}
+
 /******************************************************************************
  * CMapTable::CMapFormat0::Builder
  ******************************************************************************/
-CMapTable::CMapFormat0::Builder::Builder(WritableFontData* data,
-                                         int32_t offset,
-                                         const CMapId& cmap_id)
-    : CMapTable::CMap::Builder(data ? down_cast<WritableFontData*>(
-                                   data->Slice(offset, data->ReadUShort(
-                                       offset + Offset::kFormat0Length)))
-                               : reinterpret_cast<WritableFontData*>(NULL),
-                               CMapFormat::kFormat0, cmap_id) {
-  // TODO(arthurhsu): FIXIT: heavy lifting and leak, need fix.
+// static
+CALLER_ATTACH CMapTable::CMapFormat0::Builder*
+CMapTable::CMapFormat0::Builder::NewInstance(WritableFontData* data,
+                                             int32_t offset,
+                                             const CMapId& cmap_id) {
+  WritableFontDataPtr wdata;
+  if (data) {
+    wdata.Attach(down_cast<WritableFontData*>(
+        data->Slice(offset,
+                    data->ReadUShort(offset + Offset::kFormat0Length))));
+  }
+  return new Builder(wdata, CMapFormat::kFormat0, cmap_id);
 }
 
-CMapTable::CMapFormat0::Builder::Builder(ReadableFontData* data,
-                                         int32_t offset,
+// static
+CALLER_ATTACH CMapTable::CMapFormat0::Builder*
+CMapTable::CMapFormat0::Builder::NewInstance(ReadableFontData* data,
+                                             int32_t offset,
+                                             const CMapId& cmap_id) {
+  ReadableFontDataPtr rdata;
+  if (data) {
+    rdata.Attach(down_cast<ReadableFontData*>(
+        data->Slice(offset,
+                    data->ReadUShort(offset + Offset::kFormat0Length))));
+  }
+  return new Builder(rdata, CMapFormat::kFormat0, cmap_id);
+}
+
+// static
+CALLER_ATTACH CMapTable::CMapFormat0::Builder*
+CMapTable::CMapFormat0::Builder::NewInstance(const CMapId& cmap_id) {
+  return new Builder(cmap_id);
+}
+
+// Always call NewInstance instead of the constructor for creating a new builder
+// object! This refactoring avoids memory leaks when slicing the font data.
+CMapTable::CMapFormat0::Builder::Builder(WritableFontData* data, int32_t offset,
                                          const CMapId& cmap_id)
-    : CMapTable::CMap::Builder(data ? down_cast<ReadableFontData*>(
-                                   data->Slice(offset, data->ReadUShort(
-                                       offset + Offset::kFormat0Length)))
-                               : reinterpret_cast<WritableFontData*>(NULL),
-                               CMapFormat::kFormat0, cmap_id) {
-  // TODO(arthurhsu): FIXIT: heavy lifting and leak, need fix.
+    : CMapTable::CMap::Builder(data, CMapFormat::kFormat0, cmap_id) {
+  UNREFERENCED_PARAMETER(offset);
+}
+
+CMapTable::CMapFormat0::Builder::Builder(
+    ReadableFontData* data,
+    int32_t offset,
+    const CMapId& cmap_id)
+    : CMapTable::CMap::Builder(data, CMapFormat::kFormat0, cmap_id) {
+  UNREFERENCED_PARAMETER(offset);
+}
+
+CMapTable::CMapFormat0::Builder::
+Builder(const CMapId& cmap_id)
+    : CMap::Builder(reinterpret_cast<ReadableFontData*>(NULL),
+                    CMapFormat::kFormat0,
+                    cmap_id) {
 }
 
 CMapTable::CMapFormat0::Builder::~Builder() {
@@ -364,28 +590,6 @@
 }
 
 /******************************************************************************
- * CMapTable::Iterator class
- ******************************************************************************/
-CMapTable::CMapIterator::CMapIterator(CMapTable* table, CMapFilter* filter)
-    : table_index_(0), filter_(filter), table_(table) {}
-
-bool CMapTable::CMapIterator::HasNext() {
-  if (!filter_) {
-    if (table_index_ < table_->NumCMaps()) {
-      return true;
-    }
-    return false;
-  }
-
-  for (; table_index_ < table_->NumCMaps(); ++table_index_) {
-    if (filter_->accept(table_->GetCMapId(table_index_))) {
-      return true;
-    }
-  }
-  return false;
-}
-
-/******************************************************************************
  * CMapTable::Builder class
  ******************************************************************************/
 CMapTable::Builder::Builder(Header* header, WritableFontData* data)
@@ -403,12 +607,12 @@
   int32_t size = new_data->WriteUShort(CMapTable::Offset::kVersion,
                                        version_);
   size += new_data->WriteUShort(CMapTable::Offset::kNumTables,
-                                cmap_builders_.size());
+                                GetCMapBuilders()->size());
 
   int32_t index_offset = size;
-  size += cmap_builders_.size() * CMapTable::Offset::kEncodingRecordSize;
-  for (CMapBuilderMap::iterator it = cmap_builders_.begin(),
-                                e = cmap_builders_.end(); it != e; ++it) {
+  size += GetCMapBuilders()->size() * CMapTable::Offset::kEncodingRecordSize;
+  for (CMapBuilderMap::iterator it = GetCMapBuilders()->begin(),
+           e = GetCMapBuilders()->end(); it != e; ++it) {
     CMapBuilderPtr b = it->second;
     // header entry
     index_offset += new_data->WriteUShort(index_offset, b->platform_id());
@@ -424,12 +628,12 @@
 }
 
 bool CMapTable::Builder::SubReadyToSerialize() {
-  if (cmap_builders_.empty())
+  if (GetCMapBuilders()->empty())
     return false;
 
   // check each table
-  for (CMapBuilderMap::iterator it = cmap_builders_.begin(),
-                                e = cmap_builders_.end(); it != e; ++it) {
+  for (CMapBuilderMap::iterator it = GetCMapBuilders()->begin(),
+           e = GetCMapBuilders()->end(); it != e; ++it) {
     if (!it->second->SubReadyToSerialize())
       return false;
   }
@@ -437,16 +641,16 @@
 }
 
 int32_t CMapTable::Builder::SubDataSizeToSerialize() {
-  if (cmap_builders_.empty())
+  if (GetCMapBuilders()->empty())
     return 0;
 
   bool variable = false;
   int32_t size = CMapTable::Offset::kEncodingRecordStart +
-                 cmap_builders_.size() * CMapTable::Offset::kEncodingRecordSize;
+      GetCMapBuilders()->size() * CMapTable::Offset::kEncodingRecordSize;
 
   // calculate size of each table
-  for (CMapBuilderMap::iterator it = cmap_builders_.begin(),
-                                e = cmap_builders_.end(); it != e; ++it) {
+  for (CMapBuilderMap::iterator it = GetCMapBuilders()->begin(),
+           e = GetCMapBuilders()->end(); it != e; ++it) {
     int32_t cmap_size = it->second->SubDataSizeToSerialize();
     size += abs(cmap_size);
     variable |= cmap_size <= 0;
@@ -455,8 +659,8 @@
 }
 
 void CMapTable::Builder::SubDataSet() {
-  cmap_builders_.clear();
-  Table::Builder::set_model_changed(false);
+  GetCMapBuilders()->clear();
+  Table::Builder::set_model_changed();
 }
 
 CALLER_ATTACH FontDataTable*
@@ -473,6 +677,7 @@
   return builder.Detach();
 }
 
+// static
 CALLER_ATTACH CMapTable::CMap::Builder*
     CMapTable::Builder::CMapBuilder(ReadableFontData* data, int32_t index) {
   if (index < 0 || index > NumCMaps(data)) {
@@ -489,10 +694,11 @@
                                          OffsetForEncodingRecord(index));
   int32_t offset = data->ReadULongAsInt(Offset::kEncodingRecordOffset +
                                         OffsetForEncodingRecord(index));
-  CMapId cmap_id(platform_id, encoding_id);
-  return CMap::Builder::GetBuilder(data, offset, cmap_id);
+  return CMap::Builder::GetBuilder(data, offset,
+                                   NewCMapId(platform_id, encoding_id));
 }
 
+// static
 int32_t CMapTable::Builder::NumCMaps(ReadableFontData* data) {
   if (data == NULL) {
     return 0;
@@ -500,4 +706,64 @@
   return data->ReadUShort(Offset::kNumTables);
 }
 
+int32_t CMapTable::Builder::NumCMaps() {
+  return GetCMapBuilders()->size();
+}
+
+void CMapTable::Builder::Initialize(ReadableFontData* data) {
+  int32_t num_cmaps = NumCMaps(data);
+  for (int32_t i = 0; i < num_cmaps; ++i) {
+    Ptr<CMapTable::CMap::Builder> cmap_builder;
+    cmap_builder.Attach(CMapBuilder(data, i));
+    if (!cmap_builder)
+      continue;
+    cmap_builders_[cmap_builder->cmap_id()] = cmap_builder;
+    cmap_builders_.insert(std::make_pair(cmap_builder->cmap_id(),
+                                         cmap_builder));
+  }
+}
+
+CMapTable::CMap::Builder* CMapTable::Builder::NewCMapBuilder(
+    const CMapId& cmap_id,
+    ReadableFontData* data) {
+  Ptr<WritableFontData> wfd;
+  wfd.Attach(WritableFontData::CreateWritableFontData(data->Size()));
+  data->CopyTo(wfd.p_);
+  CMapTable::CMapBuilderPtr builder;
+  builder.Attach(CMap::Builder::GetBuilder(wfd.p_, 0, cmap_id));
+  CMapBuilderMap* cmap_builders = CMapTable::Builder::GetCMapBuilders();
+  cmap_builders->insert(std::make_pair(cmap_id, builder.p_));
+  return builder.Detach();
+}
+
+CMapTable::CMap::Builder*
+CMapTable::Builder::NewCMapBuilder(int32_t format, const CMapId& cmap_id) {
+  Ptr<CMapTable::CMap::Builder> cmap_builder;
+  cmap_builder.Attach(CMap::Builder::GetBuilder(format, cmap_id));
+  CMapBuilderMap* cmap_builders = CMapTable::Builder::GetCMapBuilders();
+  cmap_builders->insert(std::make_pair(cmap_id, cmap_builder.p_));
+  return cmap_builder.Detach();
+}
+
+CMapTable::CMap::Builder*
+CMapTable::Builder::CMapBuilder(const CMapId& cmap_id) {
+  CMapBuilderMap* cmap_builders = this->GetCMapBuilders();
+  CMapBuilderMap::iterator builder = cmap_builders->find(cmap_id);
+  if (builder != cmap_builders->end())
+    return builder->second;
+#ifndef SFNTLY_NO_EXCEPTION
+  throw NoSuchElementException("No builder found for cmap_id");
+#else
+  return NULL;
+#endif
+}
+
+CMapTable::CMapBuilderMap* CMapTable::Builder::GetCMapBuilders() {
+  if (cmap_builders_.empty()) {
+    Initialize(InternalReadData());
+    set_model_changed();
+  }
+  return &cmap_builders_;
+}
+
 }  // namespace sfntly
diff --git a/sfntly/table/core/cmap_table.h b/sfntly/table/core/cmap_table.h
index 6455ef6..2242613 100644
--- a/sfntly/table/core/cmap_table.h
+++ b/sfntly/table/core/cmap_table.h
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-// TODO(arthurhsu): IMPLEMENT: not really used and tested, need cleanup
 #ifndef SFNTLY_CPP_SRC_SFNTLY_TABLE_CORE_CMAP_TABLE_H_
 #define SFNTLY_CPP_SRC_SFNTLY_TABLE_CORE_CMAP_TABLE_H_
 
@@ -46,23 +45,12 @@
 class CMapTable : public SubTableContainerTable, public RefCounted<CMapTable> {
 public:
   // CMapTable::CMapId
-  class CMapId {
-   public:
-    CMapId(int32_t platform_id, int32_t encoding_id);
-    CMapId(const CMapId& obj);
-
-    int32_t platform_id() { return platform_id_; }
-    int32_t encoding_id() { return encoding_id_; }
-
-    bool operator==(const CMapId& obj);
-    const CMapId& operator=(const CMapId& obj);
-    int HashCode() const;
-
-    friend class CMapIdComparator;
-
-   private:
-    int32_t platform_id_;
-    int32_t encoding_id_;
+  struct CMapId {
+    int32_t platform_id;
+    int32_t encoding_id;
+    bool operator==(const CMapId& obj) const {
+      return platform_id == obj.platform_id && encoding_id == obj.encoding_id;
+    }
   };
   static CMapId WINDOWS_BMP;
   static CMapId WINDOWS_UCS4;
@@ -71,7 +59,7 @@
   // CMapTable::CMapIdComparator
   class CMapIdComparator {
    public:
-    bool operator()(const CMapId& lhs, const CMapId& rhs);
+    bool operator()(const CMapId& lhs, const CMapId& rhs) const;
   };
 
   // A filter on cmap
@@ -81,11 +69,28 @@
     // Test on whether the cmap is acceptable or not
     // @param cmap_id the id of the cmap
     // @return true if the cmap is acceptable; false otherwise
-    virtual bool accept(CMapId cmap_id) = 0;
+    virtual bool accept(const CMapId& cmap_id) const = 0;
     // Make gcc -Wnon-virtual-dtor happy.
     virtual ~CMapFilter() {}
   };
 
+  // Filters CMaps by CMapId to implement CMapTable::get()
+  // wanted_id is the CMap we'd like to find.
+  // We compare the current CMap to it either by equality (==) or using a
+  // comparator.
+  // CMapTable::CMapIdFilter
+  class CMapIdFilter : public CMapFilter {
+   public:
+    explicit CMapIdFilter(const CMapId wanted_id);
+    CMapIdFilter(const CMapId wanted_id,
+                 const CMapIdComparator* comparator);
+    ~CMapIdFilter() {}
+    virtual bool accept(const CMapId& cmap_id) const;
+   private:
+    const CMapId wanted_id_;
+    const CMapIdComparator *comparator_;
+  };
+
   // The abstract base class for all cmaps.
   //
   // CMap equality is based on the equality of the (@link {@link CMapId} that
@@ -93,7 +98,7 @@
   // with a given cmap id (pair of platform and encoding ids) no matter what the
   // type of the cmap is.
   //
-  // The cmap implements {@code Iterable<Integer>} to allow iteration over
+  // The cmap offers CharacterIterator to allow iteration over
   // characters that are mapped by the cmap. This iteration mostly returns the
   // characters mapped by the cmap. It will return all characters mapped by the
   // cmap to anything but .notdef <b>but</b> it may return some that are not
@@ -101,7 +106,7 @@
   // such to describe characters for lookup but without going the full way to
   // mapping to the glyph id it isn't always possible to tell if a character
   // will end up with a valid glyph id. So, some of the characters returned from
-  // the iterator may still end up pointing to the .notdef glyph. However, the
+  // the Iterator may still end up pointing to the .notdef glyph. However, the
   // number of such characters should be small in most cases with well designed
   // cmaps.
   class Builder;
@@ -116,11 +121,17 @@
           GetBuilder(ReadableFontData* data,
                      int32_t offset,
                      const CMapId& cmap_id);
+      CALLER_ATTACH static Builder*
+          GetBuilder(int32_t format,
+                     const CMapId& cmap_id);
 
       // Note: yes, an object is returned on stack since it's small enough.
       virtual CMapId cmap_id() { return cmap_id_; }
-      virtual int32_t platform_id() { return cmap_id_.platform_id(); }
-      virtual int32_t encoding_id() { return cmap_id_.encoding_id(); }
+      virtual int32_t platform_id() { return cmap_id_.platform_id; }
+      virtual int32_t encoding_id() { return cmap_id_.encoding_id; }
+      virtual int32_t format() { return format_; }
+      virtual int32_t language() { return language_; }
+      virtual void set_language(int32_t language) { language_ = language; }
 
      protected:
       Builder(ReadableFontData* data,
@@ -138,16 +149,31 @@
      private:
       int32_t format_;
       CMapId cmap_id_;
+      int32_t language_;
 
       friend class CMapTable::Builder;
     };
+    // Abstract CMap character iterator
+    // The fully qualified name is CMapTable::CMap::CharacterIterator
+    class CharacterIterator {
+     public:
+      CharacterIterator() {}
+      virtual ~CharacterIterator() {}
+      virtual bool HasNext() = 0;
+      // Returns -1 if there are no more characters to iterate through
+      // and exceptions are turned off
+      virtual int32_t Next() = 0;
+    };
 
     CMap(ReadableFontData* data, int32_t format, const CMapId& cmap_id);
     virtual ~CMap();
+
+    virtual void Iterator(CMapTable::CMap::CharacterIterator* output) = 0;
+
     virtual int32_t format() { return format_; }
     virtual CMapId cmap_id() { return cmap_id_; }
-    virtual int32_t platform_id() { return cmap_id_.platform_id(); }
-    virtual int32_t encoding_id() { return cmap_id_.encoding_id(); }
+    virtual int32_t platform_id() { return cmap_id_.platform_id; }
+    virtual int32_t encoding_id() { return cmap_id_.encoding_id; }
 
     // Get the language of the cmap.
     //
@@ -173,32 +199,63 @@
     int32_t format_;
     CMapId cmap_id_;
   };
+  typedef Ptr<CMap> CMapPtr;
   typedef Ptr<CMap::Builder> CMapBuilderPtr;
   typedef std::map<CMapId, CMapBuilderPtr, CMapIdComparator> CMapBuilderMap;
 
   // A cmap format 0 sub table
   class CMapFormat0 : public CMap, public RefCounted<CMapFormat0> {
    public:
-    // CMapTable::CMapFormat0::Builder
+    // The fully qualified name is CMapTable::CMapFormat0::Builder
     class Builder : public CMap::Builder,
                     public RefCounted<Builder> {
      public:
+      CALLER_ATTACH static Builder* NewInstance(
+          ReadableFontData* data,
+          int32_t offset,
+          const CMapId& cmap_id);
+      CALLER_ATTACH static Builder* NewInstance(
+          WritableFontData* data,
+          int32_t offset,
+          const CMapId& cmap_id);
+      CALLER_ATTACH static Builder* NewInstance(
+          const CMapId& cmap_id);
+      virtual ~Builder();
+
+     protected:
+      virtual CALLER_ATTACH FontDataTable*
+          SubBuildTable(ReadableFontData* data);
+
+     private:
+      // When creating a new CMapFormat0 Builder, use NewInstance instead of
+      // the constructors! This avoids a memory leak when slicing the FontData.
       Builder(ReadableFontData* data,
               int32_t offset,
               const CMapId& cmap_id);
       Builder(WritableFontData* data,
               int32_t offset,
               const CMapId& cmap_id);
-      virtual ~Builder();
+      Builder(
+              const CMapId& cmap_id);
+    };
 
-     protected:
-      virtual CALLER_ATTACH FontDataTable*
-          SubBuildTable(ReadableFontData* data);
+    // The fully qualified name is CMapTable::CMapFormat0::CharacterIterator
+    class CharacterIterator : public CMap::CharacterIterator {
+     public:
+      virtual ~CharacterIterator();
+      virtual bool HasNext();
+      virtual int32_t Next();
+
+     private:
+      CharacterIterator(int32_t start, int32_t end);
+      friend class CMapFormat0;
+      int32_t character_, max_character_;
     };
 
     virtual ~CMapFormat0();
     virtual int32_t Language();
     virtual int32_t GlyphId(int32_t character);
+    virtual void Iterator(CMap::CharacterIterator* output);
 
    private:
     CMapFormat0(ReadableFontData* data, const CMapId& cmap_id);
@@ -225,8 +282,17 @@
       virtual CALLER_ATTACH FontDataTable*
           SubBuildTable(ReadableFontData* data);
     };
+    // CMapTable::CMapFormat2::CharacterIterator
+    class CharacterIterator : public CMap::CharacterIterator {
+     public:
+      virtual ~CharacterIterator();
+      virtual bool hasNext();
+      virtual int32_t next();
 
-    virtual ~CMapFormat2();
+     private:
+      CharacterIterator();
+    };
+
     virtual int32_t Language();
     virtual int32_t GlyphId(int32_t character);
 
@@ -236,6 +302,8 @@
     // return the number of bytes consumed from this "character" - either 1 or 2
     virtual int32_t BytesConsumed(int32_t character);
 
+    virtual ~CMapFormat2();
+
    private:
     CMapFormat2(ReadableFontData* data, const CMapId& cmap_id);
 
@@ -244,14 +312,15 @@
     int32_t EntryCount(int32_t sub_header_index);
     int32_t IdRangeOffset(int32_t sub_header_index);
     int32_t IdDelta(int32_t sub_header_index);
+    void Iterator(CMapTable::CMap::CharacterIterator* output) { }
   };
 
   // CMapTable::Builder
   class Builder : public SubTableContainerTable::Builder,
                   public RefCounted<Builder> {
    public:
-    // Constructor scope altered to public because C++ does not allow base
-    // class to instantiate derived class with protected constructors.
+    // Constructor scope is public because C++ does not allow base class to
+    // instantiate derived class with protected constructors.
     Builder(Header* header, WritableFontData* data);
     Builder(Header* header, ReadableFontData* data);
     virtual ~Builder();
@@ -265,18 +334,54 @@
     static CALLER_ATTACH Builder* CreateBuilder(Header* header,
                                                 WritableFontData* data);
 
+    CMap::Builder* NewCMapBuilder(const CMapId& cmap_id,
+                                  ReadableFontData* data);
+    // Create a new empty CMapBuilder of the type specified in the id.
+    CMap::Builder* NewCMapBuilder(int32_t format, const CMapId& cmap_id);
+    CMap::Builder* CMapBuilder(const CMapId& cmap_id);
+
+    int32_t NumCMaps();
+    void SetVersion(int32_t version);
+
+    CMapBuilderMap* GetCMapBuilders();
+
    protected:
     static CALLER_ATTACH CMap::Builder* CMapBuilder(ReadableFontData* data,
                                                     int32_t index);
 
    private:
+    void Initialize(ReadableFontData* data);
     static int32_t NumCMaps(ReadableFontData* data);
 
     int32_t version_;
     CMapBuilderMap cmap_builders_;
   };
+  typedef Ptr<Builder> CMapTableBuilderPtr;
 
-  virtual ~CMapTable();
+  class CMapIterator {
+   public:
+    // If filter is NULL, filter through all tables.
+    CMapIterator(CMapTable* table, const CMapFilter* filter);
+    bool HasNext();
+    CMap* Next();
+
+   private:
+    int32_t table_index_;
+    const CMapFilter* filter_;
+    CMapTable* table_;
+  };
+
+  // Make a CMapId from a platform_id, encoding_id pair
+  static CMapId NewCMapId(int32_t platform_id, int32_t encoding_id);
+  // Make a CMapId from another CMapId
+  static CMapId NewCMapId(const CMapId& obj);
+
+  // Get the CMap with the specified parameters if it exists.
+  // Returns NULL otherwise.
+  CALLER_ATTACH CMap* GetCMap(const int32_t index);
+  CALLER_ATTACH CMap* GetCMap(const int32_t platform_id,
+                              const int32_t encoding_id);
+  CALLER_ATTACH CMap* GetCMap(const CMapId GetCMap_id);
 
   // Get the table version.
   virtual int32_t Version();
@@ -296,9 +401,11 @@
   // The offset is from the beginning of the table.
   virtual int32_t Offset(int32_t index);
 
- private:
+  virtual ~CMapTable();
+
   static const int32_t NOTDEF;
 
+ private:
   // Offsets to specific elements in the underlying data. These offsets are
   // relative to the start of the table or the start of sub-blocks within
   // the table.
@@ -411,19 +518,6 @@
     };
   };
 
-  class CMapIterator {
-   public:
-    // If filter is NULL, filter through all tables.
-    CMapIterator(CMapTable* table, CMapFilter* filter);
-    bool HasNext();
-    CMap* Next();
-
-   private:
-    int32_t table_index_;
-    CMapFilter* filter_;
-    CMapTable* table_;
-  };
-
   CMapTable(Header* header, ReadableFontData* data);
 
   // Get the offset in the table data for the encoding record for the cmap with
diff --git a/sfntly/table/table.cc b/sfntly/table/table.cc
index 7183d38..02f13e7 100644
--- a/sfntly/table/table.cc
+++ b/sfntly/table/table.cc
@@ -74,10 +74,10 @@
 
   // Note: Tables are commented out when they are not used/ported.
   // TODO(arthurhsu): IMPLEMENT: finish tables that are not ported.
-  /*if (tag == Tag::cmap) {
+  if (tag == Tag::cmap) {
     builder_raw = static_cast<Table::Builder*>(
-        CMapTable::CreateBuilder(font_builder, header, table_data));
-  } else*/ if (tag == Tag::head) {
+        CMapTable::Builder::CreateBuilder(header, table_data));
+  } else if (tag == Tag::head) {
     builder_raw = static_cast<Table::Builder*>(
         FontHeaderTable::Builder::CreateBuilder(header, table_data));
   } else if (tag == Tag::hhea) {