A Java based web proxy for assessing web application vulnerability. It supports editing/viewing HTTP/HTTPS messages on-the-fly to change items such as cookies and form fields. It includes a web traffic recorder, web spider, hash calculator, and a scanner for testing common web application attacks such as SQL injection and cross-site scripting.

Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 3300 potentially dangerous files/CGIs, versions on over 625 servers, and version specific problems on over 230 servers. Scan items and plugins are frequently updated and can be automatically updated (if desired).

The Nessus™ vulnerability scanner, is the world-leader in active scanners, featuring high speed discovery, configuration auditing, asset profiling, sensitive data discovery and vulnerability analysis of your security posture. Nessus scanners can be distributed throughout an entire enterprise, inside DMZs, and across physically separate networks.

Nsauditor Network Security Auditor is a network security scanner that allows to audit and monitor remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Nsauditor is a complete networking utilities package that includes a wide range of tools for network auditing, scanning, monitoring and more. You can discover network services and check them for vulnerabilities, list all TCP and UDP endpoints with their associated process, discover NetBios names, audit MS SQL servers, scan for common Adware traces and more.