It's Russ Cox's work. Background: http://research.swtch.com/field http://research.swtch.com/field Implementation: http://research.swtch.com/qart http://resear

It's Russ Cox's work. Background: http://research.swtch.com/field http://research.swtch.com/field Implementation: http://research.swtch.com/qart http://research.swtch.com/qart. It's all written in Go, btw. Running code, so you can try it on yourself: http://research.swtch.com/qr/draw http://research.swtch.com/qr/draw