The htt provides a large variety of HTTP-related functionality, useful for
implementing all kinds of HTTP-based tests:

- Advanced HTTP protocol handling, including ne-grained timeout handling,
  request and response validation
- Simulating clients and servers, including startup and shutdown of server
  daemons. This allows to create mock-ups of back-end systems in more complex
  test situations, for example when the tested application needs to interact
  with a 3rd-party back-end system which is not available in the testing
  environment.
- Execution of external commandline tools, using their output as request
  or response data, or for validation purposes.
- Copying stream data (e.g. from a response) and re-using it in variables.

WWW: http://htt.sourceforge.net/