Haskell

Haskell 2010 is an incremental update to the language, mostly incorporating several well-used and uncontroversial features previously enabled via compiler-specific flags.
A "Hello, World!" program in Haskell (only the last line is strictly necessary):
-- [[Type signature|Type annotation]] (optional, same for each implementation)An implementation of an algorithm similar to quick sort over lists, where the first element is taken as the pivot:
Implementations that fully or nearly comply with the Haskell 98 standard, include:
Implementations not fully Haskell 98 compliant, and using a variant Haskell language, include:
A series of languages inspired by Haskell, but with different type systems, have been developed, including:
The Haskell community meets regularly for research and development activities. The main events are: