Debian is among the most popular platforms to run GitLab on. With the stable release of Debian 8, we wanted to make sure that early-adopters could run GitLab on their new machines.
You can install Github from downloads page.
You can also install GitLab Community Edition with:
curl -s https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.deb.sh | sudo bash sudo apt-get install gitlab-ce