WebSlayer is a tool designed for bruteforcing Web Applications, it can be used for finding not linked resources (directories, servlets, scripts, etc), bruteforce GET and POST parameters, bruteforce Forms parameters (User/Password), Fuzzing, etc. The tools has a payload generator and a easy and powerful results analyzer.
The tool works with "payloads", and you must define where the payload must be inserted in the request. Once the payload is inserted the tool will generate all the request and then perform the attack. The results of the attacks will have a lot of information useful for the tester to sort the responses and make decisions.
It was created to facilitate the task in Web Applications assessments, it's a tool by pentesters for pentesters ;)