Какие системы или инструменты применялись до внедрения системы Git для контроля версий?

Before the widespread adoption of Git for version control, other systems were used, for example:

• CVS (Concurrent Versions System) — one of the first version control systems, allowing multiple developers to work on the same project.
• Subversion (SVN) — a centralized version control system that replaced CVS and provided more convenient version management.
• Perforce — a commercial system with high performance and support for large projects.

These systems were usually centralized, meaning the entire repository was stored on a server, and developers synchronized with it. Git introduced a distributed model, which significantly increased flexibility and speed in working with versions.