Burp Suite is a popular platform for performing security testing of web applications. It can also be used by a malicious party to analyze and attack web applications. Implemented in Java.
Burp Suite is a platform for performing security testing of websites, including (list taken from the Burp website):
- An intercepting Proxy, which lets you inspect and modify traffic between your browser and the target application.
- An application-aware Spider, for crawling content and functionality.
- An advanced web application Scanner, for automating the detection of numerous types of vulnerability.
- An Intruder tool, for performing powerful customized attacks to find and exploit unusual vulnerabilities.
- A Repeater tool, for manipulating and resending individual requests.
A Sequencer tool, for testing the randomness of session tokens. It can be used to test an application's session tokens or other important data items that are intended to be unpredictable, such as anti-CSRF tokens, password reset tokens, etc.
The ability to save your work and resume working later.
- Extensibility, allowing you to easily write your own plugins, to perform complex and highly customized tasks within Burp.
More information - Burp Suite on Wikipedia