Why does he have my avatar in 8-bit? Because he took an Apple //e and wrote a bootable 5.25″ Twitter floppy for it! This all makes me immensely happy, because I, too, spent my formative years in front of an Apple //e.
In his own words:
The Apple II has an 8-bit 6502 CPU running at 1 MHz, so it can literally execute thousands of instructions per second. In other words, it’s about a million times slower that the computer you are using right now. So I wasn’t about to write a networking stack or Twitter client on the Apple II itself. Just like the TweetWall the communication with Twitter would happen on a PC and the Apple is just used for display.