The Haskell Test Framework (HTF for short) lets you define and organize unit tests, QuickCheck properties, and black box tests in an easy and convenient way. HTF uses a custom preprocessor that collects test definitions automatically. HTF produces highly readable output for failing test cases: it provides exact file name and line number information, it colors and pretty prints expected and actual results, and it displays a diff highlighting the mismatching parts. The documentation of the Test.Framework.Tutorial module provides a tutorial for HTF. The sample directory in the HTF repo provides a good starting point for a project using HTF.