Scalable, simple and super fast, Ruby and Ruby on Rails is a dream team duo that offers a full stack language and framework to build full programs and web apps, fast. It’s a favourite among entrepreneurs and start ups, and has a wide selection of third-party ‘gems’ (add-ons) that can make it do pretty much whatever you need it to. Twitter and Basecamp use Ruby, so it has to be good, right? As one of the most valued and desirable skills out there, there’s no harm in learning this one.