Magic Music Visuals - Fully-customizable and highly responsive visuals for live and recorded audio & MIDI.
Annotate.tv - Optimize your learning on YouTube
projectM - projectM is an LGPL'ed reimplementation of Milkdrop under OpenGL.
Slid - Capture knowledge from online videos, courses, and webinars
Kauna - Kauna is a music visualizer. Kauna renders any sound reproduction in system.
Simply.Digital - Goals & Tasks - Todo list to track your time & help set meaningful deadlines