Heh, asking if the code is open source in this context feels like panhandling :)
UPDATE: Here it is!
https://github.com/roryok/todoscreensaver
(uses WPF/.NET, GPL, based on a WaveSimScreensaver source by Sean Sexton)
Planning a few updates already, mostly just extra settings (change font size, theme etc)
EDIT: found this blog entry on creating OSX screensavers in Swift if anyone wants to give it a go
https://whichline.wordpress.com/2015/07/13/os-x-screensaver-...
UPDATE: Here it is!
https://github.com/roryok/todoscreensaver
(uses WPF/.NET, GPL, based on a WaveSimScreensaver source by Sean Sexton)
Planning a few updates already, mostly just extra settings (change font size, theme etc)