What amazed me most is this thing's use of the 8-bit architecture that Will Not Die, the Intel 8051!
https://www.youtube.com/watch?v=bRgCvCTG_XQ&feature=youtu.be&t=23m55s
I don't know how it happened, if Intel made the design available freely or what, but there are an unbelievable number of companies that make variants of it and others that make software development tools for it.