Re-installing Essential Software

So I, like many other geeks that try to figure things out on their own but mess a few system files in the process , have been saved by some wonderful software called Pacifist by Charlessoft.com at least twice now. First my boyfriend deleted Terminal.app (which was way to easy to do even being administrator), and today I somehow couldn’t get Installer.app working correctly. Both times I ran Pacifist, got my OS X install discs, and was able to re-install the applications without completely re-installing the operating system from scratch (which would be very annoying even though I do back ups).  Definitely register the software to show your gratitude like myself!  It only runs on Mac OS X, and I’m not sure if there is a Windows equivalent.  If there is, leave me a comment on this post!