Popular Firefox add-ons and their current multi-process compatibility state

Mozilla is working on Firefox's multi-process architecture that it calls e10s and interested users can enable it in some versions of Firefox already.

If you have tried it already you may have noticed that some sites or add-ons that you are using are not working properly when e10s is enabled in the browser.

If you are interested in the progress that is being made in regards to add-ons, then you may want to head over to the Are we e10s yet website which lists popular add-ons for Firefox and their compatibility state.

There you find listed HTTPS Everywhere for example which is listed as not compatible right now. Each add-on that is not working at all or only partially has a bug assigned to it that is used to keep track of its compatibility progress.

For HTTPS Everywhere it is this bug on Bugzilla@Mozilla that you can use to keep track of the issue.

The Electronic Frontier Foundation has just released a new development build of HTTPS Everywhere for Firefox, HTTPS Everywhere 5.0 Development 1 which is e10s compatible.

Firefox users who use e10s and HTTPS Everywhere can use this build to use both together.

Note though that you are running a development version of Firefox if you use e10s already and a development build of an add-on. There is no guarantee yet that everything will work fine at this point.

HTTPS Everywhere is not the only extension that is listed as not compatible right now. If you go through the list you find a massive amount of add-ons that don't work yet including the following ones:

• All in One Sidebar, no sidebars are being displayed when e10s is active. Unknown status.
• Ghostery, visualizes web trackers. Unknown status.
• Greasemonkey, a popular program to load JavaScript on load. Is being worked.
• KeeFox, a password manager for KeePass. Unknown status.
• LastPass, the popular online password manager. Work will begin when e10s hits beta according to support.
• Lazarus Form Recovery, saves web forms so that the information can be restored. Unknown status.
• Multi Links, a mass link opener. Unknown status.
• NoScript, a script blocker that is highly popular is not fully compatible yet. The author is working on it though.
• RefControl, referrer control add-on. Status unknown, appears abandoned.
• Remove it Permanently, removes elements on web pages. Unknown status.
• Scriptish, a Greasemonkey alternative. Unknown status.
• Self-Destructing Cookies, a cookie management add-on. Analyzed currently.

This is just a small selection of add-ons that don't work at all or only partially if e10s is enabled in Firefox. Mozilla seems to have contacted authors of said add-ons and while that may work for some, it won't work at all for abandoned add-ons for obvious reasons.

There is still -- some -- time left and it is very likely that many of the extensions listed as partially compatible or incompatible will become compatible before e10s lands in Firefox Stable.

On a personal note, I had to disable e10s in Firefox Nightly recently as I ran into a series of issues that made the browser unusable for me.