SideProjects is described as 'Working on a side project is something a lot of us share. Whether it’s an open source resource, a blog, etc., all ideas, as crazy as they are, have some sort of potential' and is an website in the Office & Productivity category. There are more than 100 alternatives to SideProjects, not only websites but also apps for a variety of platforms, including Mac, Windows, Linux and Android. The best alternative is AlternativeTo, which is free. Other great sites and apps similar to SideProjects are Product Hunt (Free), Slant (Free), SimilarSites (Free) and Softpedia (Free).
AlternativeTo let you find new Windows, Mac, Linux, online and mobile software based on applications you already know instead of useless categories. AlternativeTo is a new approach to finding good software.
Its main sections are Windows, Mac, Mac PPC, Linux, Games, Handheld (mobile software), Drivers, Mobile, Webscripts, and News. It also covers technology, science, health and entertainment topics from both external and in-house sources, and it provides software and game reviews.