This site only offers games released under Sierra's older game interpreter (AGI).
The games from about 1989 onward, including QfG, used a different interpreter (SCI, which was very advanced for its time: an object-oriented VM platform with a complete GUI toolkit, running on top of vanilla DOS, years before Windows 3.0).
The SCI games can be played under ScummVM or DosBox, if you have the original binaries.
Torment is definitely in my top 5 games of all time. Hard to believe it's been out for ten years.
If you haven't played it, I highly recommend "Arcanum: Of Steamworks and Magick Obscura", developed by Troika and published by Sierra in 2001. It's very similar in depth and mechanics to Torment, Fallout, and the other Black Isle RPGs.