Very lean and fast web framework designed as a thin layer on top of Plack. The excellent documentation allows for a quick start and easy reference during development. We have most of our projects developed using Dancer, but Kelp is a great candidate for our next site. We are especially attracted to the Plack integration and the low learning curve.
We switched to Validate::Tiny from Data::FormValidator and we have been using it for a year in production now. It's incredibly stable and easy to use. We love the simplicity and robustness of this module. It's light and small, yet it allows us to build our own validation closures and perform really complicated data validation.