Al Kossow wrote: Quite a bit of it is documented by Apple itself. There are OS and Pascal Workshop manuals as well as info about the drivers from Apple itself. A few parts were disassembled by David Craig, these are/were available on the web in various forms, mostly PDF's. There are copies of the boot rom source code that are commented, and even there you can see varied styles of coding. You're talking to one of them, but I'm not ready to announce anything just yet. I'd presume that some of that may be NDA's. A lot of it could be cultural. We are now in a more open society than before (in terms of computing), where as back then things were more closely guarded. Perhaps they feel they'd be breaking trade secrets. Silly after all this time. I don't know why there should be any stigma associated with having worked on the Lisa project. The guys that built it had a huge project on their hands and were able to do some amazing things on the shoulders of what Xerox did. They got very close. But they were too far ahead of their time and Moore's Law didn't allow them to build cheap Lisa's. The Lisa OS was a lot more robust that the original Mac OS. It was close to Unix under the hood and featured things like pipes, virtual memory with paging, etc. Imagine how much effort it was to build a Unix clone out of Pascal, and then add the complexity of writing a GUI from scratch and a full set of applications too.