Why would GOG.COM omit this information from the game description? I never heard of the "masterpiece edition" and there is no further info about the contents on the game page. I must be the only gamer on earth who never heard of it. Despite having played Myst when it came out.
Thanks.

The Masterpiece Edition features graphics redone in a higher color count. The original was 256 colors, masterpiece is 16 thousand.
Other than that, probably some software differences too, but it's basically the same game.
real Myst, on the other side, is the game entirely remade in 3D, a bit uglier but awesome to play.
EDIT: http://www.mobygames.com/game/myst-masterpiece-edition
Check there for more info.

Yeah, this plays like the original one pretty much, but it's 24 bit colour instead of 8 bit (256 colours).

Ah, OK... so it is just the original Myst. I was confused because so many people seem to be talking about the other games too (Riven, realMyst, etc.) that I thought maybe this M.E. was more than just the original game (with better colors, as you say). Thanks for the clarifications!