PraxisLIVE is described as 'open-source, visual programming environment. Experiment with and create projects using a visual patching system coupled with the power of programming in Java, Processing and GLSL'. There are more than 25 alternatives to PraxisLIVE for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is Pure Data, which is both free and Open Source. Other great apps like PraxisLIVE are VCV Rack (Free, Open Source), SuperCollider (Free, Open Source), Reaktor (Freemium) and Max/MSP (Paid).
Pd (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical processing. It is the third major branch of the family of patcher programming languages known as Max (Max/FTS, ISPW Max, Max/MSP, jMax, etc.
VCV Rack is a modular synthesizer inspired by Eurorack systems. It acts a host for virtual modules which perform various audio processes. E.G. oscillators, filters, envelope generators, sequencers and more that can be connected freely in almost limitless combinations.
Native Instruments Reaktor is a virtual, modular synthesis platform. REAKTOR also provides a platform for modular synthesis in the form of Blocks – a range of sound generating and sound shaping modules.
vvvv is a graphical programming environment for easy prototyping and development. It is designed to facilitate the handling of large media environments with physical interfaces, real-time motion graphics, audio and video that can interact with many users simultaneously.
TouchDesigner is a complete authoring tool for building interactive 3D art, visualizations, prototypes and UIs. Derivative makes and supports TouchDesigner and offers their services to do custom production using TouchDesigner.
openFrameworks is an open source C++ toolkit designed to assist the creative process by providing a simple and intuitive framework for experimentation. The toolkit is designed to work as a general purpose glue, and wraps together several commonly used libraries, including: