Firefox Developer Edition
This free Mac app was originally developed by Mozilla.org. Firefox Developer Edition for Mac is included in Internet & Network Tools.
From the developer:
Firefox Developer Edition (was Aurora) is the rapid-fire release channel for the next iteration of the Firefox Web browser. The Developer channel is where users can test the latest features and innovations. Users can expect an increase in polish from the raw, cutting edge features in the nightly builds. These releases may not be as stable as beta or final releases.
You may want to check out more Mac applications, such as Firefox Developer Edition, BandDEK Editor or Firefox, which might be related to Firefox Developer Edition.