Franchise is an easy-to use package for building Haskell software. Unlike Cabal, you aren't required to track every possible dependency in every possible build condition. In addition, you are not required to use an external tool such as autoconf in order to configure the build based on which packages, libraries and tools are present.
For more information, see the rudimentary manual and test suite.
In addition, there is now haddock documentation of the franchise API.
You can get franchise with darcs using
darcs get http://darcs.net/franchise