There are comparatively a lot less than github but they do exist. Some examples of successful project using gitlab.com: Wireshark, QEMU, Inkscape, F-Droid, Aur

There are comparatively a lot less than github but they do exist. Some examples of successful project using gitlab.com: Wireshark, QEMU, Inkscape, F-Droid, Aurora, Commento, Kicad, Remmina, tortoise-git...