Eclipse is an extensible and Open Source IDE, but our main use of it is as a Java IDE.
The official webpage can be found at http://www.eclipse.org/
To get started please install Java first. See our Java install page for details.
Our recommended version is currently R2.1.3. When downloading, find the file called eclipse-SDK-2.1.3-platform.zip. For example, platform will be win32 if you are installing on windows.
Unpack this file directly to the target installation directory. There is no installation program, but some setup will run the first time you start it up.