If you're on a Unix/Linux system and you don't have Ruby installed (or you want to upgrade), your distribution's package system may make a Ruby package available. On debian GNU/LINUX, it's available as the package ruby-[version]: for instance, ruby-1.8 or ruby-1.9. Red Hat Linux calls it ruby; so does the DarwinParts system on Mac OS X.

Rails is a web development framework written in the Ruby language. It is designed to make programming web applications easier by making several assumptions about what every developer needs to get started. It allows you to write less code while accomplishing more than many other languages and frameworks. Longtime Rails developers also report that it makes web application development more fun.

"Derek Sivers, quite the Rails champion when he decided to rebuild his CD Baby e-commerce site using Rails two years ago, has now admitted defeat. After two years of wrestling with Rails while building the new site, Sivers along with coder Jeremy Kemper, decided to face up to reality. Kemper went off to 37signals and Sivers rebuilt the entire site in PHP in just two months.