jj-vcs/jj

Jujutsu, with the short command name jj, is a version control system. A version control system is the kind of tool developers use to keep a history of changes to their code, share those changes with teammates, and roll back when something goes wrong. The README pitches it as both simple and powerful, and aimed at being easy to use whether you are new or working on a large project with a long history. What makes Jujutsu different is that it separates the user-facing commands and the algorithms from the underlying place where data is stored. Today the default storage layer is a Git repository, which is what makes Jujutsu compatible with existing Git-based tools and hosting services. Higher-level information like bookmarks (its term for branches) is kept in its own storage outside Git. The README highlights several design choices it borrows or invents. There is no separate staging area, and branches can be anonymous so you do not have to name every small change. A revset language lets you select sets of commits, and a template language formats output. Conflicts are tracked as first-class objects in the model rather than just as text differences, so some conflict resolutions propagate automatically. Your working copy is itself recorded as a commit and updated on each change, which removes the need for stashes or a staging area. Every operation on the repository is logged, so you can ask what just happened and undo mistakes. Modifying a commit automatically rebases its descendants on top. Some experimental features include safe behavior when a repository sits inside a syncing folder. The project is written in Rust.