Well guys, once again I look to your collective knowledge for any recommendations you might offer...

I'm looking for server-side software that's capable of building a library of links to organizations, resources, etc that visitors can browse by category. Since each entry should be able to be listed under multiple categories, I'm guessing what I'm looking for will be database driven (flat file or otherwise).

Of course, the web pages this software produces would need to be customizable for design integration. Googling only returns results oriented toward facilitating link-exchange solutions, which isn't quite what I'm looking for. Ideally, if you guys know of solutions for both Windows and Unix-based servers, that'd be very helpful!

Thanks!