Lately I've been reading up on Amazon's Ion format and think it's underappreciated. It's got a decent spec for both binary and text serialization formats, under

Lately I've been reading up on Amazon's Ion format and think it's underappreciated. It's got a decent spec for both binary and text serialization formats, under an Apache-2.0 license even. Maybe I'm weird but I just don't like using serialization formats that don't include a specification for the binary format. I also like where Ion goes with it's symbol tables. They provide much of the space efficiency that Protobufs provide with schemas, but gives you much more freedom and flexibility. I'm a longtime fan of msgpack but it becomes inefficient if you transport field names with it. The Ion schema also seems nice as an alternative to Protobuf schemas, but able to describe arbitrary data constraints too.