Question: I would like to get an auto-updating version of Firefox Developer Edition rather than a [once-off installation](https://askubuntu.com/questions/548003). From [comments on the announcement](https://hacks.mozilla.org/2014/11/mozilla-introduces-the-first-browser-built-for-developers-firefox-developer-edition/comment-page-1/) and [this Mozilla ticket](https://bugzilla.mozilla.org/show_bug.cgi?id=1072181) it appears that Firefox Developer Edition is a rebranding of Aurora (a stable pre-release channel).

In that case, can I just install [the Firefox Aurora PPA](https://launchpad.net/~ubuntu-mozilla-daily/+archive/ubuntu/firefox-aurora) which is maintained by the Ubuntu Mozilla Daily Build Team?

Answer: 
The [OMG! Ubuntu! post covering the announcement](http://www.omgubuntu.co.uk/2014/11/mozilla-releases-firefox-developer-edition) notes that the version released is [Aurora 35.0a2](https://www.mozilla.org/en-US/firefox/35.0a2/auroranotes/) which matches [the version in the PPA](https://launchpad.net/~ubuntu-mozilla-daily/+archive/ubuntu/firefox-aurora), so it looks like this is the way to do it :)

Note that this method will replace your current Firefox installation. If you want to run "regular" Firefox and Developer Edition side-by-side you will have to [install DE separately](https://askubuntu.com/questions/548003). I don't know of a PPA for this. (Unless you have a specific requirement to run them side-by-side, this shouldn't be necessary.)
You can actually get firefox's built-in auto-update to work if you have manually installed it.

Just set the ownership and permissions so your regular user can write to the install directory. Assuming your user belongs to the `sudo` group and firefox has been installed in `/opt/firefox-dev`:

```
sudo chown -R root:sudo /opt/firefox-dev
sudo chmod -R g+rwX /opt/firefox-dev

```

You may have to restart it.