Sketch - Professional digital design for Mac.
Processing - C++ and Java programming at the speed of thought.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Vvvv - vvvv is a graphical programming environment for easy prototyping and development.
Affinity Designer - Professional creative software, exclusively for Mac.
TouchDesigner - TouchDesigner is a visual development platform that equips you with the tools you need to create stunning realtime projects and rich user experiences.