Of the Citadel Source file below, Gene Buckle writes "This is the source code to the original Citadel for CP/M, written by Cynbe ru Taren (Jeff Prothero) in 1981. All room systems are decended from either this exact code base or based upon the "room system" concept that it expresses. There are two other known versions of the original CP/M source code out there. Versions 2.15 and 2.20 have been "seen in the wild". This archive includes all documentation as well as menus and help files. A compiled Citadel is also included. It requires BDS C to compile if you're going to try it under CP/M. Leor Zolman, the author of BDS C, has make this compile available on his website http://www.bdsoft.com for free. See the entery under the "free tools" link."