OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Loxi - Easily add an events calendar to any website.
Synfig Studio - Just another WordPress site
Event Calendar App - A simple, easy to manage, way of displaying events
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Whenever - Casual calendar app for iOS