This great website can help you find open source alternatives to your favorite commercial products.
It also helps you decide whether to use open source or commercial software by offering these advantages: By choosing an open source product, the user obtains a number of advantages compared to commercial products. Besides the fact that open source is always available for free, it is a transparent application, in that you are invited exclusively behind the scenes to view all source code and thereby to suggest improvements to the product. Furthermore, every product is covered by a large dedicated network, or community, who is more than willing to answer any questions, you may have.