Mozilla Add-ons Blog

We’ve seen reports from the field and blogosphere that Firefox 3.0.1 has somehow broken compatibility for many add-ons. This is indeed not the case. When add-on authors publish their add-on they declare the compatibility range for an add-on. It typically looks like “2.0 to 3.0.*” – meaning that at minimum, this add-on requires Firefox 2.0 and works with any maintaince release of Firefox 3.0. (End of the compatibility range is also called the maxVersion).

Some add-on authors have erroneously used “3.0″ as their maxVersion so when users with these add-ons upgrade from Firefox 3.0 to Firefox 3.0.1, the add-on gets disabled. We encourage these add-on authors to use “3.0.*” as their maxVersion.

We have verified that the majority of add-ons hosted on AMO with Firefox 3 support have “3.0.*” in their compatibility range but there are many sites from where add-ons can be acquired.

Now that Firefox 3.0 Release Candidates are starting to become available, we have made modifications to AMO to accept the production version numbers for Firefox 3. In particular, we have added “3.0″ and “3.0.*” as valid Firefox compatible versions. The full application compatibility list is available here.

What this means for you as an add-on author is that after you test with the Firefox 3 release candidates, you can use the Developer Tools section on AMO to bump your version number without having to upload a new version of your add-on.

For completeness, if you want to support Firefox (and none of the alpha’s, betas and pre-releases), here are the recommended version ranges (minVersion – maxVersion) to use:

• Firefox 2: 2.0 – 2.0.0.*
• Firefox 3: 3.0 – 3.0.* (Note: that with Firefox 3, it’s a three part version number)