This document describes the approved uses of the system application programming and binary interfaces that will ensure compatibility across Red Hat Enterprise Linux releases. It outlines the tiered framework under which applications are considered compatible and not compatible.
html5 compatibility chart
Traceur is a JavaScript.next-to-JavaScript-of-today compiler that allows you to use features from the future today
manage and report firefox addon update issues
Compatibility tables for features in HTML5, CSS3, SVG and other upcoming web technologies.