Preparing for Firefox ESR 60.0

Mozilla plans to release the next Extended Support Release version of the organization's Firefox web browser, Firefox ESR 60.0, on May 9, 2018. Firefox 59.0 would have been the original target for the next ESR version but Mozilla postponed it.

Firefox ESR 60.0 is a major new release as it updates Firefox installations that are still on the feature level of Firefox 52 to Firefox 60. Changes made in Firefox 53 to 60, with the exception of security updates, will find their way into that version of the browser.

The change alone is a major one but the situation gets even more complicated in this case because Mozilla introduced major architectural changes to Firefox after the release of Firefox 52.

I focus on major changes in this guide only and how you best cope with those. You can check out the links to our release overviews at the end of the guide for additional information about each release since Firefox 52.0.

Note that you can stay on Firefox ESR 52.8 when Firefox ESR 60 is released, and stay on Firefox ESR 52.9 when Firefox ESR 60.1 is released.

Firefox ESR 60.2 will be released on August 21, 2018 and Firefox ESR installations still on 52.x at the time will be upgraded to the new version.

Here is the release schedule:

• 2018-05-09: Firefox 60, Firefox ESR 60, Firefox ESR 52.8
• 2018-06-26: Firefox 61, Firefox ESR 60.1, Firefox ESR 52.9
• 2018-08-21: Firefox 62, Firefox ESR 60.2

Preparing for Firefox ESR 60.0

I recommend that you create a backup of Firefox profiles before you upgrade Firefox ESR 52.x to Firefox ESR 60.0 as you won't be able to go back once you have upgraded to the new version.

Firefox makes changes to the user profile during the upgrade which are incompatible with previous versions of the browser.

The major changes in Firefox 60 ESR

I will cover the following changes:

• Compatibility changes in regards to supported operating systems and architectures.
• The switch from the legacy add-on system to WebExtensions of Firefox 57.
• Changes in the browser's multi-process system.
• The new policy system on Windows.
• Other relevant changes.

Compatibility changes

Mozilla dropped support for Windows XP and Windows Vista, any 32-bit machine running Mac OS X, and for Linux systems with processors older than Pentium 4 or AMD Opteron in Firefox 53.

Firefox ESR 52.x is the last ESR branch that supports these operating systems. #

In other words, Firefox ESR 60.x won't support any of the aforementioned operating systems.

Only Windows 7 or newer versions of Windows are supported by Firefox.

Legacy add-ons are out

Firefox ESR 60.0 won't support legacy add-ons. Some extensions have been updated by their developers while others have not. Many popular extensions, content blockers or password managers, have been updated.

If you ran abandoned extensions, less popular ones, or extensions that require specific APIs that are not available, you may be out of luck.

Any Firefox add-on that is not a WebExtension won't run in Firefox 60 ESR. I'm not aware of options to quickly find out if all installed add-ons are compatible with Firefox 60 or not.

This leaves heading over to the Mozilla Add-ons website to run searches for each installed add-on.

It is unclear right now whether Mozilla plans to move all incompatible extensions to a "legacy extensions" listing on about:addons. If that is the case, you may use the "find a replacement" button to get potential alternatives for the add-on.

Note that the listing becomes available after you upgrade, if it does.

Multi-process system changes

Firefox will use more processes after the upgrade. Mozilla increased the number of content processes from 1 to 4 in Firefox 54.0 and it seems likely that this will carry over to Firefox ESR 60 as well.

You may notice a new Compositor process on Windows systems besides that as it was introduced in Firefox 53.0.

The new policy system

Firefox ESR 60 comes with Group Policy support

Windows users and administrators may make configuration changes using the new option instead of using autoconfig files.

Not all options are supported but it may be a good idea to check out what is available when Firefox 60 launches as it may make things easier.

Other changes
There have been numerous changes to Firefox since the release of Firefox ESR 52.0. The following highlights major changes only:

• Firefox Quantum which made Firefox faster and more stable. Mozilla claimed that Firefox 57 with Quantum was twice as fast as Firefox 52 without it.
• Firefox Photon is a design refresh. It modified some interface areas but the general look and feel remained.
• Some new tools like the Screenshot tool are integrated natively.

Testing

You have two main options when it comes to testing the new ESR release:

1. Wait until Firefox ESR 60 is released and start to test it.
2. Use Firefox 60 Beta to run tests.

How you do it depends on a number of criteria, for example, how much time you have or need to upgrade.

I suggest you back up a Firefox profile and use it to test the new release. If you want to use Firefox ESR 60.0 for testing, you may want to use a virtual machine for that or another machine designed for testing.