Firefox has been shipping their nightly Linux builds the past three months with ForkServer enabled to improve the multi-process browser experience. The results are looking good and Firefox official releases for Linux should soon begin shipping with ForkServer too for this performance win.

Mozilla engineer Alexandre Lissy presented at the FOSDEM 2025 conference earlier this month on Mozilla's ForkServer for Linux within Firefox for improving the multi-process handling within the web browser. This is part of the evolution of the multi-process Firefox handling as a process dedicated to fork() handling that is faster and lighter weight than the status quo.

Since last October nightly builds of Firefox on Linux have begun using ForkServer. It appears to be reliable and the most important aspect for end-users is the performance wins with base resident memory around 50% lower and the content process startup is reduced by around 35%.

Those wanting to learn more about Firefox ForkServer on Linux can watch the FOSDEM 2025 presentation on FOSDEM.org .