I've been using Piqi on a side-project of mine and I must say, I'm horribly impressed (using piqi_rpc with erlang for a web service and javascript based client to retrieve/interact with the data). The only way it could be nicer is if there was the same sort of generator for javascript so I didn't end up having to check/enforce the format at all.

Didn't realize you hung out on HN, so many thanks and great job.