I do most of my work with protos in Java, and it's nice to have a schema like this that will build a bunch of immutable POJOs with builder classes and enough in

I do most of my work with protos in Java, and it's nice to have a schema like this that will build a bunch of immutable POJOs with builder classes and enough infrastructure to be able to do some interesting reflection-style stuff on top of the serialization / deserialization. The wide variety of client languages is really nice. I'm fairly certain that I can parse a proto in any language I'm ever going to use. The binary wire format is fairly straightforward, and is pretty tight without using compression. Fields are byte-aligned, and if you wanted to generate a binary proto message by concatenating a few things together it isn't very hard. And then you can use your proto definitions in whatever language you want to parse it. You can even parse your proto definition into a proto (Google provides the proto proto definitions, I think I got that grammar right) and write tools that generate whatever code you want easily. I think the text format is under-utilized. It's my go-to for configuration files. You create the proto definitions with whatever structures you want to structure your config settings, and then use the official parser to parse a text file. It supports comments (I'm throwing shade at you, JSON), and is simpler than YAML, while adding that structure. You can also use command line tools to validate the file as a pre-commit, or translate it into a binary format if you don't want to rely on the text format.