Some of the projects I am working on (this page is WIP).
pushups.sh
A git server and frontend for learning git. Every course is a repository: git clone it, read the instructions, git commit your solution, and git push to
submit. The server verifies your commits and makes the next stage available
through git pull.
The site follows your progress in real time, with repository viewing and in-line feedback. The teaching commits are layered directly on top of your own, making the repository history itself the record of your progress.