Delta (image above, video below) by Yousuke Fuyama is a software sketch for generating triangles and sounds in realtime. Beyond that I know nothing, is it for a performance or an installation? What this is made in? It might be Max/MSP or Processing using OpenCV but it could also be a number of other things (Puredata, OpenFrameWorks etc.). Yes sure I’ve seen Reactable and it’s countless imitations but nothing I’ve seen sounds as good as this.