MessagePack is an efficient binary serialization format.
It lets you exchange data among multiple languages like JSON but it's faster and smaller.
It's a pure Lua implementation, without dependency.
And it's really fast with LuaJIT.
The homepage is at http://fperrad.github.io/lua-MessagePack/, and the sources are hosted at http://github.com/fperrad/lua-MessagePack/.
Copyright (c) 2012-2013 Francois Perrad
This library is licensed under the terms of the MIT/X11 license, like Lua itself.