Developers, take note. RailSlide is a new native Ruby on Rails editor for Mac OS X. Written from scratch, in Cocoa, with Ruby on Rails in mind, the app means there’s no need for a project file.

Just drop a Rails app folder on the dock, and your app’s source files will appear in the navigation view organized by category with related models, views and controllers grouped together. Once you’ve opened a project, the development server is booted using your choice of RVM interpreter and gemset.

The output will appear in the integrated console, and any errors that occur while you test the app with the built-in browser are detected. RailSlide will direct you straight to the offending line of source code.

A demo is available at http://vallettaventures.tumblr.com/railside. The full app can be downloaded at http://itunes.apple.com/app/railside-rails-ide/id468367116?mt=12 for US$29.99.