Cap’n Proto

Cap’n Proto is an insanely fast data interchange format and capability-based RPC system. Think JSON, except binary. Or think Protocol Buffers, except faster. In fact, in benchmarks, Cap’n Proto is INFINITY TIMES faster than Protocol Buffers.

http://kentonv.github.io/capnproto/

http://kentonv.github.io/capnproto/otherlang.html