The recommended way to install Projectile is via
You can install a snapshot version of Projectile from the MELPA repository. The version of Projectile there will always be up-to-date, but it might be unstable (albeit rarely).
You can install the last stable version of Projectile from the MELPA Stable repository.
Projectile is also available for installation from the el-get package manager.
Projectile is naturally part of the Emacs Prelude. If you're a Prelude user - Projectile is already properly configured and ready for action.
Debian and Ubuntu
Users of Debian 9 or later or Ubuntu 16.10 or later may simply
apt-get install elpa-projectile.