On Nov. 4, 2011, we held a public call to evaluate options for improving Firefox responsiveness including the multi-process Firefox initiative (code name Electrolysis, also known as e10s). The outcome of this discussion was a decision to put the Electrolysis initiative on hold for the foreseeable future and focus on other initiatives aimed at improving responsiveness in the browser. As the Electrolysis program manager I would like to share the background around this decision.
The goal of Electrolysis is to separate the user interface process from the content processes (the portion of the browser that renders Web pages for display) with an aim to improve responsiveness in the user interface. There are a number of secondary program goals such as crash protection, support for multi-core machines, and sandboxing (isolating) content to improve security. (See Chris Blizzard’s goals for multi-process Firefox blog post for more details about the goals.) All of these items have technical merit and it was not the technical merit of the initiative that was under review.
Electrolysis is a huge undertaking. I can’t emphasize that point enough. Converting an established product, like Firefox, from a single- to multi-process architecture requires the involvement and coordination of many teams. Most recently I have been working with the accessibility, add-ons, front-end, graphics, and release engineering teams on various projects. Electrolysis requires a large investment of resources and time and has a long timeline for completion. How long? At this point we do not have a definitive answer as there are many unknowns that need to be investigated and addressed, such as how to ensure that add-ons can function in this new multi-process environment.
The list of responsiveness initiatives includes a number of smaller initiatives, such as out of process plug-ins (OOPP), Places-optimization, and incremental garbage collection. When looking at the investment in Electrolysis, it is quickly apparent that the talented people working on this program could instead be working on some of these smaller initiatives. We reviewed a short list of these initiatives and concluded that the results of working on the short term initiatives should provide significant responsiveness wins delivered in a shorter (known) time frame than Electrolysis. This means a more responsive Firefox will be available on your desktop sooner.