Projectile

Projectile is a project interaction library for Emacs. Its goal is to provide a nice set of features operating on a project level without introducing external dependencies (when feasible). For instance - finding project files has a portable implementation written in pure Emacs Lisp without the use of GNU find (but for performance sake an indexing mechanism backed by external commands exists as well). This library provides easy project management and navigation. The concept of a project is pretty basic - just a folder containing some special file (e.g. a VCS marker or a project descriptor file like pom.xml or Gemfile). Projectile will auto-detect pretty much every popular project type out of the box and you can easily extend it with additional project types. Projectile tries to be practical - portability is great, but if some external tools could speed up some task substantially and the tools are available, Projectile will leverage them.