Over the past three months, Firefox has enabled ForkServer in its nightly Linux builds to improve the multi-process browser experience. The results look good, and the official version of Firefox for Linux will soon start releasing ForkServer to gain performance improvements.
Mozilla engineer Alexandre Lissy introduced Mozilla's ForkServer for Linux in Firefox at the FOSDEM2025 conference earlier this month to improve multi-process handling in the web browser. This is part of the evolution of Firefox's multi-processing, which is a dedicated process for fork() processing, making it faster and lighter than the status quo.
Nightly builds of Firefox on Linux have been using ForkServer since October last year. It seems to be reliable, and the most important aspects for end users are the performance improvements, with base resident memory reduced by about 50% and content process launches reduced by about 35%.
Users wishing to learn more about FirefoxForkServer on Linux can watch the FOSDEM2025 demo at FOSDEM.org.