Apr 20, 2011 12:45 GMT  ·  By
Add-on compatibility update chart for the new rapid release cycle of Firefox
   Add-on compatibility update chart for the new rapid release cycle of Firefox

One of the big problems when upgrading from one major version of Firefox to another has always been add-on compatibility. This meant that plenty of users stuck with the old versions until add-on makers decided to update their creations.

It was a problem, but since a major version took half a year to a year and a half to bake, it was manageable. This can't work with the new rapid release system Mozilla has implemented, which is why it's being dropped entirely.

Instead, add-ons will be deemed compatible by default and only the ones reported or determined to be uncompatible will be marked as such, making for a much smoother update process for users and a lot less headaches for developers.

"In order to support this exciting new release schedule, a lot has to change, and one of the biggest areas impacted is add-on compatibility," Mozilla wrote.

"With past Firefox releases, add-ons were not marked as compatible with a new version until the developer manually tested and updated their add-on to support it," it explained.

"This process took months to get compatibility to an acceptable level and only worked because of the infrequency of Firefox releases. Our proposed plan for compatibility going forward assumes add-ons are compatible unless we find evidence that they aren’t," it announced.

There are some exceptions, not all add-ons will be automatically marked as compatible. If the automated test detects possible issues, the developer will be notified and will have to make the necessary changes.

There is another possibility, if an add-on uses a brand new API feature which later gets pulled out of the Aurora channel, because it wasn't fully baked yet, the add-on becomes compatible only with the Nightly channel.

What's more, add-ons won't be made compatible with the Nightly channel automatically, only with the Aurora channel and above. Nightly users have to disable compatibility checking to test add-ons.

The system isn't live yet, so add-ons are not going to be made compatible with Firefox 5.0 in the Aurora channel. Mozilla hopes everything will be put in place by the time Firefox 5.0 enters the Beta period.