A device programmer for the Atmel AVR
series of microcontrollers
designed by Steven Bolt.
It's a very simple device that attaches to the PC parallel port and requires only a few resistors, capacitors and a crystal. Source is available to drive the programmer under DOS and Linux. Somebody also wrote a driver to control it under NT which isn't as friendly to directly bit-banging a port.
A google search for programming a spider's brain will take you to the sp12 page. (Mr. Bolt created the sp12 to program a small robot, or 'spider'.)