I chanced on an intriguing freeware package a couple of weeks ago.
Sounds daft perhaps, but I seem not to have bookmarked the web pages
(nor can I find it in the browser history), and my mind has completely
blanked both the name and how I stumbled upon it.

It was a drawing package, allowing frames of video to be defined from
basic shapes and operations. Programmed in scheme, if I recall, and
probably intended for linux. The web site had several videos showing the
code being changed in real-time, superimposed on the resulting image output.

Can anyone recognise what it might have been from that rather scanty
description and put me out of my misery please?

Thanks!!