The latest phase of our add-on compatibility plan has arrived in Aurora, and we need your help to test it! Since Firefox 4, we have been automatically making add-ons hosted on AMO compatible with new Firefox releases. Now, we have extended automatic compatibility to non-hosted add-ons, which account for 75% of all add-ons in use (currently in the hundreds of millions). This means you should see less of the incompatible add-ons dialog, and more of your add-ons should just work.
Once you have Aurora installed, all add-ons that are compatible with Firefox 4 or later can be installed without extra steps. Firefox will install them even if they are declared incompatible in the manifest file.
If you don’t already have Aurora installed, you can get it here. With Aurora, you’ll see our newest features before they go beta, and have a chance to send us feedback before the final release.
Please send us feedback or file bugs on the new default to compatible feature here. We look forward to hearing from you!