New website of MessagePack Project introduces next-generation RPC.

It basically uses TCP. Raw unreliable UDP is also supported on Ruby and Java. TCP or UDP will be enough choices for most of applications. Practically, MessagePack-RPC mainly focuses on cross-language communication, like Ruby frontend <-> C++ backend. So portability is rather important.

It's true that network latency is dominator rather than serialization. But low CPU/memory usage is still important for CPU/memory-bound applications. Especially, zero-copy feature is effective to raise maximum throughput. As for RPC performance, parallelism will be important for high-load systems. It's described at http://msgpack.wordpress.com/2010/05/08/messagepack-rpc-for-... On the other hand, some uses serialize/deserialize directly on search engine or caching to pack objects.

Also curious about how this compares to BERT, which uses Erlang's binary term format, which makes sense to me since so much infrastructure uses Erlang these days.