One kilobyte is not much data. It's 1024 bytes, so if you think of one byte being represented by one character (not strictly correct but close), I've already wasted over 200 of them right here. It doesn't seem like you'd be able to program much with a mere one kilobyte of data, but prepare to be shocked at what's possible.
Head over to the link below to play with all of the demos yourself (most of them are interactive), and don't for a moment forget that each one was programmed using less data than it took to write the text in this article.
And now I'm depressed.