Aptana Studio provides built-in servers, code assist, page previews, debugging and more for PHP, Jaxer, Ruby on Rails, and Python. Availability variety of source control plug-ins, an integrated FTP client, and single-click browser previews for Firefox, IE and Safari will all make your life much easier.
Aptana Studio is based on Eclipse. That means you can plug it into Eclipse itself, or other Eclipse-based IDEs. You can also run a standalone edition of Aptana Studio which bundles in Eclipse 3.2, so that you can then extend Studio with other Aptana plug-ins or other plug-ins for Eclipse.
Aptana uses a “dual licensing” model. Under this model, you may choose to use Aptana Studio under the free software/open source GNU General Public License or under the Aptana Public License (known as the “APL”). APL license is for organizations that want to use Aptana Studio free of charge and modify, integrate and distribute it for personal or internal use only, without any redistribution requirements. You can find further information & download on Aptana Website.