Codeology is described as 'from Braintree creates beautiful, animated art from GitHub code'. There are five alternatives to Codeology for Online / Web-based, Self-Hosted solutions, Mac, Windows and Linux. The best alternative is Gource, which is both free and Open Source. Other great apps like Codeology are CodeFlower (Free, Open Source), Git Visualizer (Free, Open Source), GitHub Visualizer (Free, Open Source) and Github Visualize (Free).
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.