Modular Muse was developed as part of my PhD work at the ATLAS Institute which includes two platforms that can be used to develop musical robots / instruments and mapping tangible interfaces to sound:

The musical robots (instrument building) platform consists of MIDI controlled Motor Driver boards and associated laser cut mechanisms. Example projects which utilize this platform include Solidnoise, beatBox, Aesthetic Algorithms, and projects by others including a tactile interface, thermochromic display (shown below)

Sound Clippys is an instrument building platform that makes it easy to build tangible interfaces and a software library for mapping interfaces to sound. These were used in workshops and in a middle school music classroom where children designed and built their own instruments (see eCSite example video).  

Please see www.modularmuse.com for more info and to order hardware.