Distributed version control system written by Linus Torvalds in 2005 for Linux kernel development after the BitKeeper licence dispute. Its content-addressed model made every clone a full backup of a project's history — a preservation property that reshaped how software is kept and shared.
The Preservation Rating scores how well this entry is archived — not how good the software is. It's calculated automatically from what's already on this page: working mirrors, documentation, a reproducible build, a clearly identified license, and complete metadata. Nothing here is entered by hand; it updates itself whenever the entry changes.
