For all of its warts, YAML hits the sweet spot between readability, writability, commentability, and (mostly) intuitive syntax. It's easy to serialize complex objects to, and comes bundled with Ruby's runtime.
There are a lot of valid complaints about YAML, but I still reach for it when I really only need a barebones configuration file.
There are a lot of valid complaints about YAML, but I still reach for it when I really only need a barebones configuration file.