I've used Swagger before. I'm not sure it fits the bill for what you're looking for, but it has a few nice parser tools that produce good documentation and even

I've used Swagger before. I'm not sure it fits the bill for what you're looking for, but it has a few nice parser tools that produce good documentation and even a working API UI wrapper. For versioning, there's just a DSL format that is plaintext, so you can get diffs from there. http://swagger.io/ http://swagger.io/