This page gives an overview of the concept of a code "Editor" in Eclipse and Aptana.
Introduction
Code any programming language supported by Aptana and Eclipse using an "Editor". An Editor is a tab that opens in the middle of your workbench that contains the file that you are working on.
Currently, Eclipse focuses on Java editing, but provides some editing capabilities for other programming languages. Aptana focuses on web development and provides robust editing capabilities for HTML, CSS, JavaScript, and light PHP support. Aptana Rails provides Ruby on Rails support.
If you would like support for a programming language that is not provided by Aptana or your current Eclipse set-up, you can often find a "plug-in" that will provide an Editor and support for that language. To learn more about extending Eclipse via plug-ins, see About plug-ins.