Programming. Realtime computer graphics. Demoscene. Game development. Stuff.
Immediate mode GUI
It's already advertised somewhere else, but I'll add it as well: Casey Muratori has an amazing lecture on Immediate Mode GUI. I like the idea, and while I think IMGUI mostly applies to realtime UIs (in-game, editors etc.), this is a good read (er... watch) for any UI programmer.
I was subconsciously heading towards that UI style as well; drawing and processing some UI "immediately", though not at the level Casey does.