As we mentioned previously, Mozilla will be introducing multiprocess Firefox (e10s) to selected users with the release of Firefox 48. Installations of Firefox that do not have add-ons installed or accessibility features enabled will have multi-process support enabled by default over the next six weeks. We’ll be testing multiprocess Firefox with add-ons in the release channel starting in Firefox 49, with the intent to make it the default for all installations of Firefox in early 2017.

While a number of existing add-ons will work with multiprocess Firefox, some will not work, or will not work well. We’d like add-ons to “just work”, so users will be able to use all their favorite extensions while experiencing the benefits of e10s as it’s rolled out to them. To this end, we have an urgent request for developers of add-ons who have not tested their add-ons for e10s compatibility or switched to WebExtensions already:

Then, take one of the following paths:

If your add-on works as expected with e10s, mark it as multi-process compatible and upload the new version to AMO and/or your updateURL

with e10s, mark it as multi-process compatible and upload the new version to AMO and/or your updateURL If your add-on doesn’t work as expected with e10s, adapt it to work with e10s, mark it as multi-process compatible and upload the new version to AMO and/or your updateURL

Additional information on e10s, add-ons, and WebExtensions are available on a Mozilla Wiki and MDN, and we’re also here to help you make the transition. While it seems far away, 2017 is just a few months away, and we’d ask that you test—and update, if necessary—your add-ons as soon as possible.