It still surprises me that not many people working in, or have interest in, IT have been introduced to what is probably the best fusion of tech and art, ever since the invention of the modern day PC. I’m talking, of course, about the demoscene. To spare you the click out, here’s a definition from Wikipedia:
The demoscene is a computer art subculture that specializes in producing demos, which are non-interactive audio-visual presentations that run in real-time on a computer. The main goal of a demo is to show off programming, artistic, and musical skills.
debris. by farbrausch
From a technical standpoint, the creations are nothing short of impressive. You see, in the majority of demos, no bitmap textures or pre-rendered music are ever used. Rather, all textures are procedurally generated by the CPU and delivered directly to the graphics card, and the music is also synthesized in real-time. This leads to demos that are minuscule in size (usually less than 100kb, some even as little as 4kb). This limitation was in part because the programmer wanted to push his skills to the test and use as little resources as possible, but mostly it was because of hardware limitations of early 80s PCs.
From the artistic side, demos are quite spectacular as well. Original animation, music and 3D modeling, all envisioned by the programmer. 
The demoscene just might be the geekiest of all arts.
I got introduced to it sometime in 1999 (late bloomer, I know) on my Windows machine, and the stuff I saw, blew me away. I was never too hardcore about it, but I generally revisited the two main sites that distribute demos:
To this day, a few demos stand out for me after all these years:
- fr-025: the.popular.demo [8.4M] by farbrausch: Absolutely amazing production. Doesn’t go for minimal size, but the music is flawless (pre-rendered, I believe), animation spot-on, and the lighting effects second to none. It’s widely popular (hence the name), and usually shown first to newcomers to the scene.
- fr-041: debris. [177k] by farbrausch: Just incredible. Again, farbrausch prove they’re kings of production. Awesome lighting effects and incredibly detailed modeling. All in 179k. Stunning demo (if you have the hardware to run it on).
- .kkrieger [beta] [96k] by .theprodukkt: Another creation from the same team as the above two. This is a game. First-person shooter comparable in graphical quality to Doom3. In 96k. Mind=blown.
There are countless more, and you could spend days browsing pouet.net seeing all the amazing stuff.
Chiptune
Chiptune is a subset of the demoscene, which specializes in producing synthesized music that runs on limited hardware sound chips. These, again, are all procedurally generated and require quite a bit of know-how of math, algorithms, programming and details about the specific hardware you’re using.
There are countless of good tunes out there, but my favorite ones have always been these two:
They come from a Class installer circa ’00 for a game rip of THPS2. I remember keeping the installer running in the background just so I could listen to these tracks. I miss those days… :’-(
You can play them with any module file player. On Windows, I recommend foobar2000 with the foo_dumb plugin. VLC plays them too, albeit shitty.
PROTIP: If your machine is too slow to run any but the oldest of demos, you can watch videos of the most popular ones on demoscene.tv. But it’s just not the same as actually knowing what you’re seeing is being generated on-the-fly by your machine, and especially seeing the 4kb file that does it. :-O