"Microsoft MS-PL Controls: Instead of reimplementing the
high-level controls (buttons, Checkboxes, listboxes, containers,
calendars, datepickers, sliders) or the very advanced controls
(like a full database bound datagrid) Moonlight reuses Microsoft's
open sourced Silverlight controls.
"Iron* Languages: In addition to C# you can run code written in
a variety of programming languages that target the ECMA CLI. In
particular dynamic languages. IronRuby and IronPython are open
source implementations of Ruby and Python done by Microsoft that
can be used in Silverlight but you can also use a variety of other
languages in the browser like Visual Basic or PHP (Phalanger).
"Visual Basic Runtime: This is just a plug for the work that
Mainsoft did a few years ago. One of the things that Silverlight
ships with is a Visual Basic class library for all the VB helper