A most generous soul named David Hammerton had created a "wrapper around Apple's mDNS Windows library (dnssd.dll) which provides two .NET classes, very similar to Cocoa's NSNetService and NSNetServiceBrowser". Since we were already familiar with Cocoa's classes, this was even easier for us.
And after many months of working with the library, and slowly testing it, and improving it, we're happily releasing an updated version of it today!
We've added several things, such as the ability to update TXT records after publishing, and the ability to monitor TXT records for updates. We also improved the speed of resolving a service, fixed a few bugs, and added some minor improvements. (The download also contains a detailed change log.) The result is a library that's almost a replica of what's been available on every Mac since 2002. :)
Download it HERE
The download comes as a zipped visual studio solution. Inside are 3 projects. 1 is the actual Zeroconf dll library. The other is a sample app to publish a service, and also includes code to later update the TXT record. The third is a sample app to browse for services, resolve services, and monitor TXT records for updates.
The solution will open just fine using the free Visual C# express. Also, I've left the compiled versions in their respective build\Release folders just in case you don't feel like compiling.
To use these, you will need to install Bonjour for Windows.
These changes have also been reported to the original author. If you have questions regarding the code, you can contact either the original author, or us.
PS - for those who don't know, Zeroconf (zero configuration networking) is a technology that allows you to automatically discover services on a local network. It's what iTunes uses to automatically find other iTunes shares. Apple's named it's particular implementation Bonjour.
-- UPDATE --
The code now has it's own Google Code Project. Check it for the latest updates.
-- UPDATE 2 --
The project now has it's own Google Groups Mailing List. Please use the mailing list for questions, comments and general troubleshooting.