R4 is described as 'Standalone OpenGL accelerated program (created by Gordon Williams of RabidHaMsTeR.Org) which aims to produce animated 3D graphics in real-time that twist and turn with the music. The WinAmp-based precursor to R4 (R2/Extreme) is now used in many nightclubs, at parties' and is an app in the os & utilities category. There are more than 25 alternatives to R4 for a variety of platforms, including Windows, Android, iPhone, iPad and Steam apps. The best R4 alternative is MilkDrop, which is both free and Open Source. Other great apps like R4 are projectM, WaveBar, Kauna and VZX Music Visualizer.