I've used a lot of JSON. It's OK. No comments, not many data types. But the spec is only a couple pages, and I've never been in doubt about how something sho

I've used a lot of JSON. It's OK. No comments, not many data types. But the spec is only a couple pages, and I've never been in doubt about how something should be escaped, or parsed. I could probably write a bare-bones parser in an afternoon, if I needed to. I've tried to work with YAML a few times. The tree structure and extra data types are great. Everything else is a huge pain. There's at least 3 versions of the spec, and the latest one is nearly 100 pages. The parts I need are always in some "extension", so there's even more that I need to support. It has a system for serializing native Objects, so you have to be careful with untrusted data because there are some interesting security issues. It's so complex, I have trouble knowing what to quote, or how. It's not feasible to write your own parser in any reasonable amount of time. Worst of all, every parsing library is slightly different, so (not unlike SOAP) you kind of have to know that it's going to be parsed with (say) PyYAML. Complicated configuration is indeed a problem in any format, but YAML makes even simple things complex. From the beginning, I really wanted to like YAML. Unfortunately, I think their goals (human-readable text, language-agnostic, rich data types, efficient, extensible, easy to implement, easy to use) are impossible. You simply can't achieve all of them at once.