The article traces how a 2005 BitKeeper licensing dispute sparked the creation of Git, how Facebook’s massive monorepo crippled Git’s performance and led it to adopt and heavily extend Mercurial into Sapling, and how Google’s even larger codebase forced a clean‑room rebuild of a new VCS called Piper.
The article traces how the 2005 BitKeeper controversy sparked the creation of Git and Mercurial, then explains why Facebook’s massive monorepo forced it to abandon Git for a heavily customized Mercurial fork (Sapling) and why Google ultimately built its own version‑control system, Piper, after outgrowing both Git and Perforce.
Facebook originally used Git but switched to Mercurial around 2012 because its massive monolithic repository caused severe performance bottlenecks, especially during file stat operations, and Git’s maintainers were unwilling to improve scalability, leading the team to evaluate alternatives like Perforce before adopting Mercurial’s clearer architecture and collaborative community.
The article investigates why Facebook abandoned Git in favor of Mercurial, detailing performance bottlenecks with massive repositories, alternative tool evaluations, the migration process, and how human factors and collaboration shaped the final decision.
Greg Foster investigates why Facebook abandoned Git for Mercurial, revealing that massive repository size caused severe performance bottlenecks, Git’s inability to scale, and the collaborative culture of Mercurial’s maintainers, ultimately shaping Facebook’s tooling decisions and influencing broader industry practices.
The article explains how Facebook abandoned Git for a heavily customized Mercurial and how Google, facing similar monorepo scaling problems, built its own version‑control system called Piper, illustrating the challenges of managing ultra‑large codebases at internet giants.
The PyPy team migrated its main codebase and issue tracker from Mercurial to GitHub, citing better visibility, CI integration, and community workflow compatibility, while reflecting on past migrations and the trade‑offs between Mercurial and Git for open‑source development.
Git is now used by 94% of developers, while GitHub is retiring its Subversion support; this article traces the evolution from centralized systems like SVN to distributed tools such as Git and Mercurial, explains why Git dominates the market, and examines the shifting landscape of version control.
This guide explains how to clone the OpenJDK 8 and 8u repositories using Mercurial, set up the environment, and compile the source code with the standard configure and make process, noting that parallel builds are not supported.
