RubyMine is described as 'JetBrains RubyMine — Ruby and Rails IDE built on years proven IntelliJ platform' and is an app in the Development category. There are more than 10 alternatives to RubyMine for a variety of platforms, including Mac, Windows, Linux, BSD and iPad. The best alternative is Atom, which is both free and Open Source. Other great apps like RubyMine are Eclipse (Free, Open Source), Geany (Free, Open Source), Aptana Studio (Free, Open Source) and TextMate (Free, Open Source).
Aptana Studio is a complete web development environment that combines powerful authoring tools with a collection of online hosting and collaboration services that help you and your team do more. Includes support for PHP, CSS, FTP, and more...
TextMate brings Apple's approach to operating systems into the world of text editors. By bridging UNIX underpinnings and GUI, TextMate cherry-picks the best of both worlds to the benefit of expert scripters and novice users alike.
TweakStyle is an Integrated Development Environment for Web Development. Unlike most IDEs, TweakStyle is tailor-made for Front-end Development and understands Web Design. It tends to packs all you need to code, preview and debug web pages with the perfect blend of features.