Do you ever wonder how programs make it through the testing process? Mozilla’s decision to speed up development of the Firefox browser gives users an unique opportunity to get a close look at this process. But despite the much-vaunted emergence of developmental builds like Firefox Beta and Firefox Aurora for wider public consumption, there’s still a lot of testing to be done even before a version of Firefox reaches alpha, or Aurora, status.
This testing is done using nightly builds – developers make changes to the code during the “day”, and then at “night” a fresh build is uploaded to the Mozilla servers for developers and hardcore enthusiasts to test. It’s important to know at this point that many of the code changes have not been tested – they’ve been incorporated into the main build, but that’s it. It's now up to the hardy souls who run Firefox Nightly to try out the changes and report back on any stability issues they encounter.
The Nightly build will install alongside other Firefox builds, specifically the Aurora build and the Beta/Stable build. However, it will share access to existing Firefox settings, meaning there is a risk you could lose these if something catastrophic was to happen.
With this in mind, we’d strongly recommend you only install Firefox Nightly on a test machine, or in a virtual environment such as that provided by VirtualBox. Once done, you can safely road test it, secure in the knowledge you’re not going to screw up your main computer by doing so.
What can you expect in the Nightly build, aside from stability issues? What you will see is a new Permissions Manager, which was introduced in version 6, which allows you to configure privacy settings such as cookies and pop-up behaviour for individual websites instead of globally. At time of writing, version 7 appears identical to version 6, but this will change over the coming days and weeks, and Firefox Nightly, once installed, will update automatically to take these into account.
This version requires a 64-bit version of Windows or Linux; other users should install the 32-bit build instead.
Most people should leave Firefox Nightly well alone, but if you’re experienced enough and dead keen to contribute to Firefox’s development, it’s worth checking out – with care.