I am proud to announce a new utility here on Ookii.org: FormatC.
FormatC is a utility that allows you to add syntax highlighting to your C#, Visual Basic, C++, XML, HTML, Transact-SQL or PowerShell source code, so you can publish it on a web page or blog post.
Why does the world need yet another syntax highlighter? Mainly, because of none of the existing .Net based ones had the features I needed. That's right, FormatC is the utility I've been using to format source code for my own blog. So if you read my site you've already seen many examples, including this one which demonstrates one of those features I mentioned: Visual Basic XML literals. I dare say I'm one of the first to actually support that, although it does have some limitations (which are mentioned on the FormatC page). In fact, I have support for all C# 3.0 and Visual Basic 9.0 features, including Linq.
You can format your source code using the interface on my site and simply copy/paste the results into a webpage or blog post, and customize the highlighting by editing the provided style sheet (or simply keep the default). You can also download FormatC as a class library to use in your own application, or look at the source code. It's designed to be easily extensible, so you can add your own languages if you want.
If you use it, let me know what you think.