C4-PlantUML combines the benefits of PlantUML and the C4 model
a parametric 3D CAD modeler
Audio Editor
Another drawing editor for LaTeX with PSTricks & TikZ
Image viewer/editor specialized in astrophotography 16bits processing
Full featured MUD server with all the trimmings.
3D Charts - Templates for PovRay(TM)
Free macro creation tool
Supporting 4op instruments, two effect columns and instrument macros.
MIDI multi track song writing in an ASCII editor!
A LaTeX library to draw all sorts of dependency trees and graphs