Yellow Lab Tools : Online test to help speeding up heavy web pages
WebScarab : WebScarab is a framework for analysing applications that communicate using the HTTP and HTTPS protocols.
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...
Which loads faster? : Pages compete head-to-head in your browser to see who's fastest!
Pa11y : Monitor the accessibility of your websites with pa11y-dashboard, and protect against accessibility errors creeping into your codebase.
Mink is an open source acceptance test framework for web applications, written in PHP 5.3.