webhint : webhint is a linting tool that will help you with your site's accessibility, speed, security and more, by checking your code for best practices and co...
Diagnostic.css : Diagnostic.css is a stylesheet which allows the user to test for common errors in a page's markup.
Also : https://github.com/karlgroves/diagnostic.css
Subgraph Vega : Vega is an open source platform to test the security of web applications. Vega can help you find and validate SQL Injections, Cross-Site Scripting (XS...
Mink : Mink is an open source acceptance test framework for web applications, written in PHP 5.3.
Nikto2 : Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6500 potent...
Monitor the accessibility of your websites with pa11y-dashboard, and protect against accessibility errors creeping into your codebase.