The Arch User Repository (AUR) is a community-driven repository for Arch Linux users. It contains package descriptions (PKGBUILDs) that allow you to compile a package from source with makepkg and then install it via pacman.[1]
The Arch User Repository also has it's own voting system where users can vote for packages and after reaching certain amount of popularity can enter the extra repository. However, the package must have a compatible license and good packaging technique, it should also be maintained actively. The packages that enter the extra repository can be directly installed by pacman.
- ↑ "Arch User Repository". Arch Linux.