Compilr

Compilr is an online IDE allowing developers to build and compile projects online, without the need of adding a bloated compiler to their system. Being web based, it is completely OS independent, meaning you have the ability to build using your favorite programming language from virtually any compatible web browser. You can currently compile Java, C#, VB .NET and XNA. It can be used as an IDE for Java, C#, VB .NET, XNA, Ruby, and PHP.

URL: www.compilr.com