Raspberry Pi: yes, of course! That’s one of the hottest platforms we’re targeting now. We’re one step away from releasing Glitch version 1, that would be shipped as a command-line app for Linux (including RPi/arm), Windows and Mac, as well as a simple GUI (using Electron). Command line app would be much faster and much more flexible, because it can be controlled over network using OSC protocol.
Arduino is not as lucky, though. Glitch songs can quickly become too heavy for an Arduino, so I doubt that will be supported (at least the small AVR-based boards). There is a chance that we will support more powerful Arduinos (Genuino, MKR boards, Yun etc), but we don’t have such boards at hand, so I can’t promise much.
Fortunately, Glitch is open source and the core of it (expression language and audio-related functions) is only 3 files in plain C, so it should be easy to port it to any platform.