Abandonware DOS title

The most popular Engine: Z-machine games

The Z-machine was developed by Infocom and used in its interactive fiction games. Z-machine is a virtual machine that allows a developer to easily develop text-adventures for multiple platforms without much hassle. A number of interpreters exists so you can play both old and new text adventures on dead platforms as well as recent ones: Glulx, Inform, TADS, etc.
infidel-1

Infidel

DOS19833.3/5 Infocom
seastalker-01

Seastalker

DOS19844/5 Infocom
suspect-01

Suspect

DOS19844.2/5 Infocom