Some time ago I met a guy on the internetz that was quite fond of demoscene. I never looked at it before, but since then,, I'm quite amazed by everything related to demos.
BIG BIG respect.
From programming techniques, to creativity. Raymatching, compressing, and music. Everything pushed to its limits.
There's been a recent thread in HN, with a quite a few links to tutorials, videos.
And here's the freaking amazing demo that started the hn thread. Prepared to shit bricks? All that thing fits in 4096 bytes.