Mercurial at FOSDEM 2026#
FOSDEM 2026 featured three compelling presentations about Mercurial, showcasing its ongoing innovation, performance improvements, and the impact of Rust integration. All talks were delivered by core Mercurial developers Raphaël Gomès and Pierre-Yves David, both from Octobus.
1. Mercurial, 20 years and counting: how are we still alive and kicking?#
Speakers: Raphaël Gomès, Pierre-Yves David Track: Main Track Video: Watch here
This keynote talk explored Mercurial’s remarkable resilience and continued relevance in the version control landscape. The speakers addressed common misconceptions about Mercurial’s vitality, reflecting on its 20-year history, community impact, and technical evolution. Key topics included:
How Mercurial has weathered the rise of Git and maintained its niche
The influence of large companies on the project’s direction
What attracts users to Mercurial in 2026
The future of version control and the role of community-driven open source
This session is a must-watch for anyone interested in the history and future of version control systems.
2. Rust in Mercurial: the wider benefits#
Speaker: Raphaël Gomès Track: Rust Video: Watch here
This talk highlighted the transformative impact of Rust on Mercurial’s codebase. Since its introduction in 2017, Rust has enabled significant improvements beyond just performance gains. The speakers discussed:
Maintainability and dependency management
API redesigns and advanced algorithms
Safe parallelism and on-disk data structures
How Rust has helped Mercurial achieve its ambitious performance goals
The session provided a unique perspective on integrating Rust into a large, mature Python codebase, offering valuable insights for developers working on similar projects.
3. Pulling 100k revisions 100× faster#
Speaker: Pierre-Yves David Track: Software Performance Video: Watch here
This performance-focused talk showcased Mercurial’s dramatic improvements in data exchange speed. The latest version (7.2) introduced optimizations that reduced the time for complex benchmark cases from nearly four hours to just two minutes—a 100× speedup. The speakers explored:
Challenges in exchanging data in a distributed version control system
High-level logic changes and low-level algorithmic improvements
Leveraging programming language strengths and modern CPU architecture
Future directions for further performance enhancements
This talk is ideal for developers interested in performance optimization and distributed systems.
Conclusion#
These presentations underscore Mercurial’s continued innovation and relevance in the version control space. Whether you’re a long-time Mercurial user or new to the ecosystem, these talks offer valuable insights into the project’s past, present, and future. Don’t miss the opportunity to learn from the core developers driving Mercurial forward!