Eclipse is an open source interactive environment for application development. The default IDE is for Java developers and is called Java Development Tools (JDT). However, the extensible plug-in system allows varous languages to be supported, including ADA, C, C++, COBOL, JavaScript, Python, Perl, PHP, Ruby, Scheme and others. The IDE is often called Eclipse ADT for Ada, Eclipse CDT for C, Eclipse JDT for Java and Eclipse PDT for PHP.

The versatile plug-in system allows the Eclipse IDE to be further tweaked to suit any developerment requirement. Multiple plug-in modules for Eclipse already exist and are actively developed. Developers can also easily write and contribute their own plug-in modules for others to use.

Although mainly known as the Java IDE, Eclipse is actually much more than just and IDE. Eclipse is an open source community whose projects are focused on building an extensible development platform, runtimes and application frameworks for building, deploying and managing software across the entire software lifecycle. Released under the terms of the Eclipse Public License, Eclipse is free and open source software.