<img src='http://kentonv.github.com/capnproto/images/infinity-times-faster.png' style='width:334px; height:306px; float: right;'> Cap'n Proto is an insanely fast data interchange format and capability-based RPC system. Think JSON, except binary. Or think [Protocol Buffers](http://protobuf.googlecode.com), except faster. In fact, in benchmarks, Cap'n Proto is INFINITY TIMES faster than Protocol Buffers. [Read more...](http://kentonv.github.com/capnproto/)