QTads is a so called "interpreter" for games created with the Text
Adventure Development System, or "Tads" for short, a C-like object
oriented programming language for authoring Interactive Fiction
(similar to the Infocom or Legend Entertainment games, like "Zork").

The Tads compiler creates executables for the Tads Virtual Machine (the
"Tads VM").  QTads is an implementation of this Virtual Machine; it
runs Tads VM programs.

Both Tads 2 as well as Tads 3 games are supported.