Firefox evolved over years from a single-process to a multi-process browser and while this brought nice improvements to the processing and latency, creating new processes has a cost both in time and in memory. This talk will introduce the solution that is coming to Linux and has already been enabled by default on Nightly for a few months: ForkServer, a process dedicated to making fork(). We will first go through a quick history of the landscape both in concurrent browsers as well as in previous attempts in Firefox and highlight the general architecture before sharing a few challenges met.