I've been using Liberator successfully in production for a while now. It's a great framework if you want just the bare bones e.g. if you're building a RESTful web service or something similar. It's essentially a wrapper for ring and compojure and provides a decision graph when validating incoming requests. It's also extremely fast compared to other more bulky web frameworks. If you want to start somewhere fast and slowly build out then Liberator is a great choice.
