CVS was the first widely used version control system that allowed developers to work concurrently on projects. It originated from Dick Grune's version control system developed in 1986 to collaboratively work with students on a compiler project. CVS evolved from shell scripts to a C implementation and became widely adopted in open source projects due its ability for distributed developers to access a shared code repository and merge concurrent changes. CVS served as a complete record of a project's history and versions through its client-server model that allowed developers to check out, modify, and commit code changes to the central repository.