Have you ever tried to find a freeware alternative to commercial software? You could try searching through Google, but Alternativeto has been set up for just such a purpose. This site has tons of great handpicked software. Each application has multiple identifiers, like license information and compatible operating systems. They also have an identifying logo, description, and normal taxonomy tags. Each application page lists all of the alternatives that match it. An alternative is any application that performs the same primary function as the application it is associated with. For instance, if you're getting tired of iTunes being slow you can search for iTunes at Alternativeto's website and you'd get a list of programs including: VLC, Songbird, and Foobar2000.

What really makes Alternativeto useful are the community features. Registration with the site is very simple. It supports OpenID (including Google and Yahoo) and Facebook Connect. So if you have one of these accounts already registering for Alternativeto is a snap. After registering you can submit your own applications if you can't find them already on the site. Each app is equipped with a comment system. The other really neat feature is the rating system. No fivestar here, just a simple "Like" interface. If you like an app, click the heart and it gets added to your likes and gets a point. An application is ranked based on the number of likes it gets.

Alternativeto categorizes its site by desktop / mobile apps, then based on platform (Windows, Mac, Linux, and Cloud).