[Six](https://github.com/randx/six https://github.com/randx/six) is typically my go to library. I really prefer something to just store rules, and six does just

[Six](https://github.com/randx/six https://github.com/randx/six) is typically my go to library. I really prefer something to just store rules, and six does just that. No fancy dsl, no integration with Rails, etc.