Moonlight: Web Applications for All Systems

Moonlight is a portable version of Silverlight running on Windows, Linux and MacOS. It provides a framework for developing rich Web application.

It is written in C++ for a third and C# for two-thirds. It depends on Mono, Cairo for the rendering engine, GTK+ for the graphics library.
Under Linux and MacOS, you have just to install the plugin for Firefox to integrate the Mono virtual machine. On Windows you should install Silverlight instead.

Moonlight 2.0

Version 2.0 is available since Silverlight 3 in December 17, 2009. It is a complete break with version 1.0 then there will be little difference for version 3.
It includes a limited version for the Web of Microsoft CLR, which allows the use of languages other than JavaScript.
Deep Zoom allows effects of magnifying images.

Other implementations added:

Moonlight 3.0

It will provide support for the H.264 video codec and AAC.

Note that an agreement has been reached between Microsoft and Novell to port Silverlight 4 under Mono: there will be a Moonlight 4!

Resources