Yes, you can now compile your C# or VB.NET code online, simply put your code in the provided text box and click “Compile Now” button. Compilr will compile your code and provide you the link as well to download complied version of your code. Any error while compilation will display error message on page.

URL: Compilr

NAnt is powerful scripting tool designed for developers, software process engineers, and build specialists to create an automated, repeatable process for building their developed application. Though its do assist developers to automate those same mundane tasks every evening but still most hesitate to use this tool their software developer process. NAnt provides powerful XML-based scripting and some really cool features, as Jean-Paul Boodhoo explains in his series of post “Automating Your Builds With NAnt”, which can streamline your development effort dramatically.

Automating Your Builds With NAnt – Part 1
Automating Your Builds With NAnt – Part 2
Automating Your Builds With NAnt – Part 3
Automating Your Builds With NAnt – Part 4
Automating Your Builds With NAnt – Part 5
Automating Your Builds With NAnt – Part 6
Automating Your Builds With NAnt – Part 7

Here is a useful .NET utility if you only want to test 8 line code and without getting involve in launching that bulky VS.NET, and then creating project etc.

URL: Snippet Compiler
Download: 2.0.8.3 for .NET 2.0 | 2.0.7.1 for .NET 1.1

Some of the interesting features I like in Snippet Compiler:
> It minimize to the system tray of task bar.
> It can also builds WinForm EXEs, console EXEs or DLLs.
> You can compile multiple C#, VB.NET ASP.NET code.
> It can be used to store templates library as well.
> IntelliSense for static members and method
> You can also export your snippet in HTML format which can be post in your blog.