Github Visualize is described as 'beautiful visual app for your Github repos'. There are five alternatives to Github Visualize, not only websites but also apps for Self-Hosted solutions, Mac, Windows and Linux. The best alternative is Gource, which is both free and Open Source. Other great sites and apps similar to Github Visualize are CodeFlower (Free, Open Source), Git Visualizer (Free, Open Source), GitHub Visualizer (Free, Open Source) and Codeology (Free, Open Source).
Software projects are displayed by Gource as an animated tree with the root directory of the project at its centre. Directories appear as branches with files as leaves. Developers can be seen working on the tree at the times they contributed to the project.