RubyMine

RubyMine is a full-fledged Ruby on Rails IDE that brings the whole range of essential developers tools for productive Ruby development and Web development with Ruby on Rails. Key features include:

• Intelligent Editor: code completion, code snippets and automatic refactorings
• Project Navigation: wide range of views and one-click jumping between components
• Error-Free Coding: on-the-fly code analysis and type inference
• Web Development with Ruby on Rails (including best-of-breed HTML, CSS and JavaScript editing support)
• RSpec, Cucumber and Test::Unit support, with GUI-based test runner
• Ruby Debugger: full support for Rails applications debugging and easy-to-use interface
• VCS Integrations: Git, Perforce, Subversion and CVS with changelists and merge

RubyMine is an annual subscription that starts at $89/year. View the pricing page.