Has been done and discussed (flamed) ages ago, in the early Windows demos era. An operating system has a lot of “free” data, graphical or otherwise (from wallpa

Has been done and discussed (flamed) ages ago, in the early Windows demos era. An operating system has a lot of “free” data, graphical or otherwise (from wallpapers to icon resources), which can be used directly or processed into something else. The code to access them cam become too big, but hacks are possible. There's also a question of fonts. Is it OK to use them to “just put some text on screen”, is it OK to use them as a source of all kinds of curves? It is hard to define where “the program” ends, and the rest of the system starts. After all, they all need to load libraries to interact with GPU into their process space. Those libraries have debug functions, example data, and other junk which is not used to put pictures on screen, but is available. Then what if a tiny application links to 50 system libraries only to have a database of potentially suitable data sequences here and there? And long before that, even regular software on microcomputers struggling to save each byte relied on known values being in known locations in ROM. It worked, because each device came from the factory with the same firmware, and it could never ever be changed for the reason I've just mentioned. The solution turns out to be pretty simple: if you think you're smart, other smart people will study your trick, and decide whether it's impressive, or just a one-time joke. Formal rules for demoparties don't mention many possible “size extending techniques” because it's generally accepted that they won't help much compared to what can be done in the same amount of bytes directly by a competent author.