SimpleGUI is a cinder block for creating minimalist GUIs. It is branched from the MowaLibs cinder implementation from Marcin Ignac, which is based off of controlIP5 for processing written by Andreas Schlegel. It has been branched here since the original repository doesn't appear to be accepting pull requests and has fallen out of date.
MowaLibs by Marcin Ignac http://marcinignac.com/blog/simplegui/
controlIP5 by Andreas Schlegel http://www.sojamo.de/libraries/controlP5/