ATLauncher is described as 'Minecraft launcher that allows you to easily play modded Minecraft'. There are more than 10 alternatives to ATLauncher for a variety of platforms, including Windows, Linux, Mac, Minecraft and BSD. The best alternative is PolyMC, which is both free and Open Source. Other great apps like ATLauncher are MultiMC (Free, Open Source), GDLauncher (Free, Open Source), Technic launcher (Free) and Crystal Launcher (Free).
Minecraft game launcher. The main features of the launcher are the same as the official launcher, including managing game versions, player profiles, and launching Minecraft. ChunkLauncher also supports Minecraft Forge game versions.