PHP is the most popular scripting language for websites, and runs on Linux hosts primarily but also on Windows and is a major success story for open source. The PHP interpreter is written in C and the language pretty easy to pick up.Just add the $ sign before variables and you are 90% of the way there!
I've written a few websites in PHP but it's not my favorite language; I find it somewhat inconsistent and you need to be aware of security issues with filtering user inputs etc. Generally I've found it runs better on Linux; there are fewer issues than on windows.
However, Phalanger is a project developed by students of Charles University, Prague to make PHP a .NET language, it's PHP written in C#. This gives possible greater speed of .il, the use of .NET functions for strings etc and of course better security. Of course .NET already has ASP.NET and ASP.NET MVC and IIS can run PHP but choice is almost always better.
- Link to C# Code Library