TestEngineering/UI/AMO/AddonCompatibleByDefault

Compatible by default

The vast majority of add-ons work from one version of Firefox to the next without the need for developer maintenance, but under the current system, compatibility information must be updated in order for Firefox to enable the add-on for use. For add-ons hosted on AMO, this is done automatically. However, 75% of add-ons in use are not hosted on AMO, and are therefore a major compatibility obstacle for our users. All of the compatibility effort put into each release is simply because Firefox still assumes add-ons will be incompatible between versions, when they usually aren't.

We should change Firefox's assumption to be that add-ons are compatible, with a few exceptions. Binary add-ons are never compatible between releases and are also the highest risk of negative side effects. Firefox should automatically enable low-risk (non-binary) add-ons in new versions of Firefox, and check AMO for additional compatibility information.

When users upgrade to a new version of Firefox, only the add-ons that are actually incompatible should be disabled, and the rest are assumed to be compatible. Because Nightly, Aurora, and Beta users will test out the add-ons for weeks before stable users, we should be able to identify and blacklist incompatible add-ons before stable users would be affected by a truly incompatible add-on.