@hackage yesod0.5.0

Yesod is a framework designed to foster creation of RESTful web application that have strong compile-time guarantees of correctness. It also affords space efficient code and portability to many deployment backends, from CGI to stand-alone serving.

The Yesod documentation site http://docs.yesodweb.com/ has much more information, tutorials and information on some of the supporting packages, like Hamlet and web-routes-quasi.