Most developers today know Git.

But before Git became the industry standard, another Distributed Version Control System (DVCS) was competing closely with it:

Mercurial (Hg)

Interestingly, companies like Meta and Mozilla trusted Mercurial for large-scale engineering workflows involving massive repositories and thousands of developers.

That raises an interesting question:

If Git became the default standard, why did some elite engineering teams still choose Mercurial?

The answer reveals important lessons about:

• developer experience
• scalability
• engineering workflows
• ecosystem adoption
• distributed systems thinking

What is Mercurial?

Mercurial is a Distributed Version Control System created in 2005.

Like Git, it allows developers to:

• track code changes
• collaborate across teams
• create branches
• merge changes
• maintain project history

But Mercurial had a different philosophy:

prioritize simplicity and usability.

Why Developers Loved Mercurial

One thing many engineers appreciated about Mercurial was its cleaner workflow.

Example:

bash
hg status
hg commit
hg pull
hg update