RTCmix is a computer music software that looks like a new version of Cmix (by Paul Lansky), but able to work, unlike its predecessor, even in real time.
Brief history – RTcmix was developed in the late nineties by Brad Garton and David Topper, Department of Music at Columbia University in New York. Deeply attached to the program Cmix, RTcmix born from the need to exploit the potential of new computers, with a better performance, small size and greater economy. Although RTcmix has been presented as a new software, its relationship with Cmix is so strong that it must be considered as a new software version of Paul Lansky. RTCmix, in fact, was not only able to manage the sound material made with Cmix but was also able to create files compatible with its predecessor. Added to this, the two shared a common library of software tools and units generatos. Both, finally, were made available for free, with source code.
Differences – It is clear that the main difference was related to the mode of use. If Cmix was designed to operate in deferred time, RTcmix was designed for real-time, allowing not only sound synthesis and control but also to work on externally loaded sound materials.
Further developments – During the years, David Topper has continued to work for the improvement of RTcmix. Among the subsequent upgrades, worth mentioning SLINC at least, a GUI designed for the graphical control of RTCmix’s parameters. Kostas Tsahalinas, however, has designed AULOS: a software able to interface with RTCmix, dedicated not to computer music composition, but to the analysis of the ancient Hellenic music repertoires. More orientated to the composition, however, is HULA, the software developed by John Gibson and designed to create textures of music loops. Even the latter, of course, was interfaced with RTCmix. It should be noted, finally, the work done by Mara Helmuth to interface RTcmix with Patchmix, already adopted by Cmix.
For this topic I’ve read:
 Brad Garton, David Topper, RTCmix – Using Cmix in Real Time, Proceedings of International Computer Music Conference, 1997, Thessaloniki.
 David Topper, Slinc 1.0: a Gui for Controlling Synthesis and Linking Instruments in RTCmix, Proceedings of International Computer Music Conference, 2000, Berlino.
 John Gibson, Loop-based Composition with RTCmix and Hula, Proceeding of International Computer Music Conference, 2000, Berlino.