Electrolysis, or e10s, is still in active development and original plans to release it with an earlier version of the browser has to be delayed.
As it stands right now, e10s is enabled on Nightly versions of the web browser by default. Mozilla enabled the architecture on Nightly versions of Firefox back in November 2014 and pushed out updates related to it regularly to the channel.
Development alone has been tricky enough but what made this an undertaking of epic proportions was that many add-ons are affected by the switch.
Mozilla keeps track of add-on compatibility on the are we e10s yet page and if you compare the state of add-ons a couple of months ago to today, you will notice that compatibility has improved.
Not all add-ons are compatible yet though and many have not even been tested for compatibility. Major add-ons, like NoScript, Multi Links, Privacy Badger, Remove it Permanently or ChatZilla are not compatible yet (you find them listed at the end of the page now).
What this means is that the add-ons won't work at all or only partially if you enable multi-process architecture in Firefox.
Mozilla plans to ship the next Developer Edition of Firefox with Electrolysis enabled. The next version, Developer Edition 40, will be released on Tuesday 12 along with updates for all other Firefox channels.
Along with it goes a change in how e10s is highlighted in the browser. All tabs were underlined up until now when the multi-process architecture was enabled in the browser.
This was removed in recent Nightly builds and there is currently no visual indicator anymore that provides you with the information.
The option to launch a new e10s window was removed as well from the browser. There is however still an option to launch a new non-e10s window as it may be useful for testing purposes.
While e10s will likely ship with version 40 of the Developer Edition of Firefox, it won't make its way down to Beta and Stable right then if it does.
The current schedule is to deliver e10s in Firefox Beta 41 and Firefox Stable 42. If all things go well, e10s may land in Firefox 42.
Bugs or issues may delay the deployment of e10s, even the launch in the Developer Edition may be delayed depending on that.
What is clear however is that development is coming to an end and that a release of e10s this year seems feasible (Firefox 43 is the latest release version that ships this year which means that Mozilla has that buffer when it comes to shipping Electrolysis this year). (via Sören Hentzschel)
Now You: Have you tried Electrolysis yet in Firefox?