Happstack itself is a web framework created in Haskell. Happstack Lite is an easier version to use that can import features from the heftier version if need be.
Ranked in these QuestionsQuestion Ranking
Pro Has extensive documentation
There is extensive documentation and tutorials for Happstack and Happstack Lite available for use. Documentation and tutorials help programmers write their code; with so many options, programmers will have an easy time learning the framework.
Pro Molded through 7+ years of feedback
Happstack has been around for over seven years. During this time developers used the framework and offered feedback to improve it. As a result, it is stable and unlikely to have major changes. Happstack Lite was created from all of this feedback
Pro Shares all of its components on gitHub
Having open source means that developers can customize the framework and offer suggestions and solutions to the code.
Con Handles exceptions poorly
When an exception occurs on the server, the error gets printed. By seeing an error that makes no sense to the user, his experience is negatively impacted. Having a negative experience can mean a user never visits the site again.
Con Allows bad code by not enforcing logic separation
Happstack allows developers to write code for controllers, routing, and models together. Doing so will dirty the code and make maintenance harder.