Currently use QC to make custom layers for Bonix TV - a vision mixing kind of application for OS X with a kind of QC stack of layers, each layer being a composition with published ports and some protocols for data types. Also generate sports graphics and twitter feeds and so on for video score boards at large sporting venues.
Spent a few years learning Quartz Composer as my way back into coding from a decade away doing design related work. Film, graphics, studied Architecture for a few years and got involved in publishing then film. Now moving into front side web development. Hope to get into app dev with Vuo and rapid app prototyping.