Firefox Nightly (will be 56) already no longer supports addons which are not multiprocess-compatible. And Firefox 57 will not support “Legacy” addons – those which use XUL, XPCOM or the Addons SDK. I just started using Nightly instead of Aurora as my main browser, at Mark Mayo’s request :-), and this is what I found (after doing “Update Addons”):
- Addons installed: 37
- Non-multiprocess-compatible addons (may also be marked Legacy): 21 (57%)
- Legacy addons: 5 (14%)
- Addons which will work in 57, if nothing changes: 11 (29%)
Useful addons which no longer work as of now are: 1-Click YouTube Video Downloader, Advertising Cookie Opt-Out, AutoAuth, Expiry Canary (OK, I wrote that one, that’s my fault), Google Translator, Live HTTP Headers, Mass Password Reset, RESTClient, and User Agent Switcher.
Useful addons which will also no longer work in 57 (if nothing changes) include: Adblock Plus, HTTPS Everywhere, JSONView, and Send to Kodi.
I’m sure Adblock Plus is being updated, because it would be sheer madness if we went ahead and it was not being. As for the rest – who knows? There doesn’t seem to be a way of finding out other than researching each one individually.
In the Firefox (I think it was) Town Hall, there was a question asked about addons and whether we felt that we were in a good place in terms of people not having a bad experience with their addons stopping working. The answer came back that we were. I fully admit I may not be a typical user, but it seems like this will not be my experience… :-(