Firefox Developer Edition An enhanced version of Firefox browser aimed at developers with tools, improved backend and debugging for HTML, JavaScript and CSS with a built-in style editor.
Firefox Flagship web browser from Mozilla based on Gecko with password manager, improved security, fast web browsing, add-ons and development tools.
Adobe Flash Player Debugger Even though Adobe has ended Flash, there is still a debugger available for anybody wishing to play these proprietary files and identify and fix issues.