Perro is a light server built on top of mongrel that helps at least one developer be happy. If it had been designed as production server it would have a cooler name. Like "Dinosaur" or "Freckle". The Internet is a global system of interconnected computer networks. Developer creates files that are served through this global system. Developer may be tempted to develop such files by creating a folder, moving the files to such folder, double clicking them and watching what happens on the browser whose address bar reads "file:///Users/cohitre/development/my-project/index.html". Perro helps developer be happy by helping overcome temptation.