AlternativeTo (http://alternativeto.net/) is a collaboratively filtered database of open-source alternative software to expensive computer programs: i.e., it’s an essential bookmark.
The site’s layout is inviting and easy to navigate: Type in the alternative software you would rather not purchase (e.g. Final Cut Pro, which costs $1,299) and you will be presented with a wide array of substitutes (e.g., a free open-source editing program called Avidemux). The site’s choices are listed according to user ratings, and it relies on the public to contribute newly discovered alternatives. It’s like an online flea market: You never know what gems you’re about to stumble upon.