Mozilla Firefox Aurora is a developmental channel for new Mozilla Firefox releases. It is designed to showcase the more experimental builds of Firefox. The Aurora channel allows users to experience the newest Firefox innovations in an unstable environment and provide feedback on features and performance to help determine what makes the final release.
What's new in this version:
Version 21.0a2 has enabled WebRTC by default, enhanced three-state UI for DNT, and changed ability to restore removed thumbnails on new tab Page.