To get in on the pre-release fun, head over to Mozilla’s new channels page and download the channel of your choice (note that, because this is the beginning of the first cycle, there currently is no beta release).
Firefox has long had the concept of release “channels,” though they did not work exactly like what Google Chrome users are accustomed to until now. From here on out Mozilla is patterning its development releases after the model pioneered by Chrome. The chief difference from the old model is that Aurora and its ilk will not require freezes on the mozilla-central repository.
In other words, like Chrome, the nightly channel might be at Firefox 7, while the Aurora channel might still be at Firefox 6, the beta channel at Firefox 5 and so on. Aurora, the new channel in the mix, is designed to bridge the wild-west bugginess of the nightly channel and the much more stable beta channel.
There two possible gotchas for users who want to try out the Aurora or beta channels. The first is add-ons; it’s unlikely that most add-ons will stay up to date with the earlier builds found in Aurora. In my testing, Ad Block Plus was the only add-on out of the seven I use that worked with Aurora. While it won’t guarantee that your add-ons work, you can install the Nightly Tester Tools add-on to override the version check.
The other, and possibly more serious gotcha is that all the channels, by default, will use the same Firefox profile, which means that there might be profile issues if you are regularly switching between a stable Firefox release and Aurora builds.
Fortunately, you can configure Aurora to use a different profile. All you need to do is grab the Firefox Profile Manager and follow the instructions for creating a new profile. Then copy all the info from your default profile into the new one. The next time you start Aurora it will ask which profile you’d like to use. Just pick the newly created profile and you’re done. Now you don’t need to worry about Aurora rendering your profile folder incompatible with other Firefox channels.
Like Chrome, Mozilla plans to update each channel roughly every six weeks. In the case of Aurora, Mozilla will do a bit of quality assurance testing before pushing out new release, but expect Aurora builds to be rougher around the edges than what you might be used to with beta releases. Still, if you’re looking for the latest in new Firefox features and emerging web standards support, Aurora is looking like the channel of choice.