2010-07-06 version 0.5.1:

  * Add msgpack_vrefbuffer_new and msgpack_vrefbuffer_free
  * Add msgpack_sbuffer_new and msgpack_sbuffer_free
  * Add msgpack_unpacker_next and msgpack_unpack_next
  * msgpack::unpack returns void
  * Add MSGPACK_VERSION{,_MAJOR,_MINOR} macros to check header version
  * Add msgpack_version{,_major,_minor} functions to check library version
  * ./configure supports --disable-cxx option not to build C++ API

2010-04-29 version 0.5.0:

  * msgpack_object_type is changed. MSGPACK_OBJECT_NIL is now 0x00.
  * New safe streaming deserializer API.
  * Add object::object(const T&) and object::operator=(const T&)
  * Add operator==(object, const T&)
  * MSGPACK_DEFINE macro defines msgpack_object(object* obj, zone* z)
  * C++ programs doesn't need to link "msgpackc" library.