Git

Game to learn git
https://ohmygit.org/

Searching for code in history
https://stackoverflow.com/questions/2928584/how-to-grep-search-through-committed-code-in-the-git-history

CLI tool for git
https://jonas.github.io/tig/

git grep <regexp> $(git rev-list --all)

Uncommit wrong branch, move changes to other branch

git reset HEAD~1
git checkout SOMEBRANCH
git commit

Restore modtime
https://stackoverflow.com/questions/21735435/git-clone-changes-file-modification-time

apt-get update ; apt-get install -y git-restore-mtime
git restore-mtime