Download Zed Attack Proxy (ZAP)

The Zed Attack Proxy (ZAP) is an easy to use integrated penetration testing tool for finding vulnerabilities in web applications.It is designed to be used by people with a wide range of security experience and as such is ideal for developers and functional testers who are new to penetration testing.ZAP provides automated scanners as well as a set of tools that allow you to find security vulnerabilities manually.

Some of ZAP's features:
Intercepting Proxy
Active scanner
Passive scanner
Brute Force scanner
Spider
Fuzzer
Port Scanner
Dynamic SSL certificates
API
Beanshell integration
ChangeLog