This was the same data -- source code and some playable game files -- but with every version separated out and tagged. Release date, release type (alpha/beta/etc), game file version, all the information I could find.
Since 2019, people have sent me a fair number of pointers to "new" source code. Some of these were previously collected in various places; some have been dug out of MIT tape archives. I've been adding them to the page as they came in.
Want a quick tour?
We now have four versions of MDL Zork -- the "mainframe Zork" from MIT. These are dated 1977, 1978, 1979, and 1981.
You may know that the game was called "Dungeon" for part of its history. Of these four, the 1977 and 1978 versions introduce themselves by saying "Welcome to Dungeon"; the 1979 and 1981 versions say "Welcome to Zork".
I've also collected as much ZIL documentation as I could find from around the Net. This includes Infocom's specifications for the Z-machine, various tutorials and reference manuals for learning ZIL, and so on.
Finally, a couple of versions of the ZAP assembler. This is the stage of the ZIL compiler which converts Z-machine assembly into a playable game file. We've got a 1982 version written in PDP-10 assembly; I mentioned that a couple of months ago.
We've also got a version of ZAP from 1988 -- late in Infocom's history. This is interesting because it's written in C! Okay, it's K&R C and probably can't be compiled without a lot of tweaking. But it's very nearly modern.
There are even compiled binaries in the folder. The folder was originally called "sun", so we presume that these are SunOS binaries from a Sun workstation. (SunOS was Sun's Unix platform, later renamed Solaris.)
The comments say "Zinn Computer Company, for Infocom", implying that the work was outsourced. There are a few other programs lying around the folder as well; apparently tools for splitting up game files into (for example) Apple or Mac floppies.
None of this is revolutionary, but it's nice to get more versions of things under the same roof.
Thanks to Lars Brinkhoff, Torbjörn Andersson, Jason Self, and (as usual) Jason Scott.