Mercurial

Mercurial is an open‑source distributed version control system (DVCS) designed to help developers and system administrators efficiently manage source code, branches, and project history. Created in 2005 by Matt Mackall, Mercurial quickly established itself as a serious alternative to Git and Subversion thanks to its simplicity, performance, and reliability.

Even today, Mercurial remains in use in demanding professional environments, especially by large organizations that need a robust, fast, and extensible open‑source solution. In this review we will analyse its key features, show how to install it, examine real‑world use cases, and compare it with other solutions available in 2025.

What problems does Mercurial solve?

IT professionals and developers face several challenges:

• Proprietary solutions such as Perforce or Bitbucket Server can be costly.
   
• Some tools like Git have a steep learning curve, hindering adoption by less‑experienced teams.
   

• Older systems like Subversion (SVN) lack modern features (offline work, lightweight branches, performance on large repositories).

Mercurial addresses these problems by offering an open‑source platform that provides:

• Open source and free of charge.

• Performance even on very large repositories.

• Ease of use with intuitive commands.

• Flexibility thanks to its extensions.

Key features and capabilities

• Interface and ergonomics

  • Simple, consistent commands (hg clone, hg commit, hg push).

  • Clear, built‑in documentation.
     
  • Compatible with graphical interfaces such as TortoiseHg.
     

• Performance

  • Optimised for large projects (e.g., Mozilla used Mercurial for Firefox for many years).
     
  • Fast handling of branches and history.
     
• Customization and extensibility
   
  • Large library of official and community extensions.
     
  • Ability to tailor the workflow to each team and each open‑source community.
     

• Security

  • Encrypted transport support via HTTPS and SSH.
     
  • Repository integrity verification.
     

How to install and configure?

1. Download Mercurial from the official Mercurial SCM website.

2. Install via package manager:

   • On Linux : sudo apt install mercurial (Debian/Ubuntu) or sudo dnf install mercurial (Fedora).

   • On Windows : install TortoiseHg which includes Mercurial.

   • On macOS : brew install mercurial.

3. Configure your identity:
   hg config --edit [ui] username = Nom Prénom <email@exemple.com>

4. Create a repository:
   hg init mon-projet 
hg add fichier.py 
hg commit -m "Premier commit" 

Use cases for Mercurial

• Collaborative software development: used by Mozilla for more than a decade for Firefox.
   
• Private repositories in companies that prefer simplicity over Git.
   
• Open‑source projects that need a clear, extensible open‑source service.
   
• IT teams seeking an alternative to Git with comparable performance and reliable technical support.
   

Comparison with alternatives

Advantages and disadvantages

Conclusion 

Mercurial remains a reliable, high‑performance, open‑source version‑control solution for developers and system administrators looking for an alternative to Git. Its ergonomics, speed on large repositories, and simplicity make it an ideal tool for professional teams and open‑source projects.