Have you done any reading on this? There's plenty of info out there.
Rails is another server-side programming language that can be used to do the sorts of things you might do with PHP, for example. Many sites are powered by Rails, and there is a CMS (or two) that runs on it as well. You need to make sure it's installed on your server before you can use it for a website, though (and unlike PHP, many hosts don't have it ready to use by default).