This is one of the most useful sites I've run across on the web.

http://alternativeto.net/

It's basically a user-generated cross reference database of programs. Search either by typing in the type of program ("DVD", "paint", etc) or the name of a program ("Microsoft Word"). Sort results after clicking on a title by tag, license, or platform (includes cloud-based programs).

Looking through the site usually nets me all sorts of programs that I've never heard of but are very good alternatives. You could use it to look for a cheaper commercial programs but I usually use it to find freeware and open source software.

Quote from website:

AlternativeTo is a new approach to finding good software. Tell us what application you want to replace and we give you suggestions on great alternatives! Instead of listing thousands of more or less crappy applications in a category, we make each application into a category. Think of it like forever evolving blog posts about good alternatives to the software that you're not satisfied with. And the "blog posts" are generated by you through suggestions, comments and votes.

(Site is constantly being updated with new entries- Suggest your own if you see missing titles)

So far, it looks like a really good site. I like the fact that it's submitted by users to.

thanks

nice site, looks better than osalt.com, which does the same but I don't think is updated often.

nice share !!
thanks you :)

Thanks, this is pretty neat site.

Cool, thanks.

Nice site thanks!

very useful site, i'll be sure to utilize it soon!

thank you