Because Steve Jobs viewed the folks who worked on the original Mac as being nothing less than artists, he famously had the Mac team sign their names to the inside of the rear panel casing on the Mac.
Since the Macintosh team were artists, it was only appropriate that we sign our work. Steve came up with the awesome idea of having each team member's signature engraved on the hard tool that molded the plastic case, so our signatures would appear inside the case of every Mac that rolled off the production line. Most customers would never see them, since you needed a special tool to look inside, but we would take pride in knowing that our names were in there, even if no one else knew.
So what's with the photo above, the one depicting an original Mac with a plethora of signatures all on the outside?
Well, that comes courtesy of Mark and Tom Frikker. Tom recently traveled to Cupertino to partake in the Mac's 30th birthday festivities and brought along with him a shell casing from an original Mac 128k. During the festivities he was able to get 25 signatures from folks involved in the creation of the Mac, a nice homage to the original Mac.
The signatures attained include actual developers along with some management personnel, including and Andy Hertzfeld, Daniel Kottke, Bill Fernandez, Bill Atkinson, John Sculley, Randy Wiggington, Mike Markkula, Chris Espinosa, and Bruce Horn.
Here are some close-up views of the signatures.
MacRumors has a great recap of the Mac's 30th birthday festivities over here, an event featuring over 100 folks who helped create the Mac.