HTTP Debugger - Debug HTTP API calls to a back-end and between back-ends. Easy of use, clean UI, and short ramp-up time. Not a proxy, no network issues!
Qualys - Qualys helps your business automate the full spectrum of auditing, compliance and protection of your IT systems and web applications.
Google Chrome Developer Tools - Get started with Google Chrome's built-in web developer tools.
Burp Suite - Burp Suite is an integrated platform for performing security testing of web applications.
Firefox Developer Tools - Examine, edit, and debug HTML, CSS, and JavaScript on the desktop and on mobile.
OpenVAS - The Open Vulnerability Assessment System (OpenVAS) is a framework of several services and tools...