w3af, is a Web Application Attack and Audit Framework. The w3af core and it’s plugins are fully written in python, it identifies more than 200 vulnerabilities and reduce your site’s overall risk exposure. Identify vulnerabilities like SQL Injection, Cross-Site Scripting, Guessable credentials, Unhandled application errors and PHP misconfigurations.
Some of the features are: fast HTTP requests, integration of web and proxy servers into the code, injecting payloads into various kinds of HTTP requests etc.
It has a command-line interface, works on Linux, Apple Mac OS X and Microsoft Windows.