Happstack Lite - 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.
Scotty - Scotty is a Haskell framework inspired by Ruby's Sinatra.
Yesod - Yesod is a development tool used to create highly efficient websites and web applications from the ground up. Yesod includes almost everything you need to build a website, from templates to routing and execution. Read more about Yesod.
IHP - The fastest way to buildtype safe web apps 🔥
Servant - servant is a set of libraries that makes building Haskell webservices a breeze.
Apiary - Collaborative design, instant API mock, generated documentation, integrated code samples, debugging and automated testing