GitLearner

Most people learn Git from documentation and then meet it for the first time on a real repository, where a wrong command can cost work. Git is also hard to picture: staging, branches, merges, and remotes are invisible until something goes wrong. The goal was a place where beginners could practise every command safely, see what each one actually does to the repository, and progress from their first `git init` to rebasing and cherry-picking - without installing anything.

The core is a Git simulator that runs entirely in the browser: state machines for the repository and a virtual file system (`ls`, `cd`, `mkdir`, `touch`, `rm`, `mv`), so commands respond instantly and nothing touches a real repository. Branch graphs, a working-directory-to-remote flow diagram, and push/pull animations make each command visible. On top of it sits a 24-lesson path across four levels. Lessons unlock in order, the terminal only accepts commands the learner has already been taught, and completion is detected automatically from the commands they type. All lesson content, cheat sheets, tips and landing-page sections live in PostgreSQL behind a NestJS API, so content changes never need a frontend deploy. For collaboration, a Socket.IO gateway runs server-side Git state for shared rooms, so several learners can clone, push, pull and hit real merge conflicts together. Stuck learners can ask for progressive hints generated by Claude and cached in Redis. XP, achievements, a public leaderboard, weekly challenges and verifiable certificates keep people coming back.