These games must be played with an AdvSys game interpreter; the standard interpreter is 'advint'. The source code for AdvSys is in programming/advsys.
BUSTED! release 1 - psychedelic interactive fiction by Scumbag Software, Inc. (Jon Drukman). Machine-independent data file for AdvSys 1.2
Elves '87, by BOA! (Burnt Out Adventurers! aka Bruce MacKay and Marlene Abriel). AdvSys source code and compiled .dat file (version 1.2), because this game is too large to be compiled under DOS. (Thanks to David A. Graves!) (an AGT version is in games/source/agt/elf.zip)
Same contents as above.
The Key to Time, by Jon Drukman. Machine-independent data file for AdvSys 1.2. (a solution is in solutions/keytime.sol)
The Sound of One Hand Clapping - A Riddle in Subtlety. Release 1a, by Erica Sadun: This file contains the machine-independent AdvSys 1.2 data files and source code of the AdvSys interpreter for Unix. (Also includes a demo of the game Pirating.)
The Sound of One Hand Clapping - A Riddle in Subtlety. Release 1a, by Erica Sadun: This file contains the machine-independent AdvSys 1.2 data files, source code of the AdvSys interpreter for DOS, and a DOS executable of the AdvSys interpreter. (Also includes a demo of the game Pirating.)
Starship Columbus version 1.2, by Gary McGath. Machine-independent data file and DOS executable of AdvInt. This game is Shareware; at some point it requires you to send $10 to the author so you can continue playing the game.