Original author(s) Platform Portable | Development status Beta Available in Haskell | |
Stable release 7.0 / March 29, 2012 (2012-03-29) Operating system | ||
Happstack (Haskell Application Stack) is a free application server for websites written in the functional programming language Haskell. It integrates handling Web, persistence, XML/XSLT, and templating functionality.
It makes use of a number of Haskell libraries and systems such as Parsec, Cabal, Template Haskell, and monad transformers ("Your app then is just a set of state transformer functions (in the MACID Monad) that take an event and state as input and that evaluate to a new state, a response, and a (possibly null) set of sideeffects.") among others.
Relation to HAppS
Happstack is the continuation of the HAppS project. The project name was changed to highlight the transition to a more open development model and a change in project leadership. The transition was made with the blessing of Alex Jacobson, and the HAppS developers are still involved in the coding.