Software to calc and draw astrological charts and diagrams according to the API method. It's written in python, it uses gtk/cairo, it depend on pytz, the swiss ephemeris and public geo data compiled anew.
Sheet Music Viewer shows a series of pictures related by name and number. Numbering is from 1 to 9. I developed it for using with my band and have found it an excellent tool. See it at martintw.com
vuVolume is a framework for volume rendering algorithms in C++. When creating a new rendering method in vuVolume it is possible to just concentrate on the actual algorithm and let the framework take care of the more administrative tasks.
I am no longer working on PhotoDirectory; I have changed my digital photo workflow, and am now relying on embedded metadata as the primary classification method, with directory structure for easier browsing. See http://image-tagger.sourceforge.net
Venn diagrams are an interesting method for rendering triadic relations on a two dimensional drawing surface. Certain marks (or annotations) indicate the existence of variables or constants in the distinguishable regions.