Well this is something of a surprise, the classic Baldur's Gate: Dark Alliance appeared on Steam just recently and it seems the developer is ensuring there will be a Linux port too.
Originally released in 2001 for the PlayStation 2, Xbox and later other consoles it recently saw an improve re-release for the latest generation of consoles. Black Isle Studios are now bringing it to Steam, with the store page going live just recently and going by the store page trailer it will go to GOG too but no store page there yet.
Black Isle Studios have been working on older titles a fair bit recently, bringing more retro games to Steam with Interplay and this is another that will have a Linux version.
"Experience the massively popular world of Baldur's Gate as never before. Baldur's Gate: Dark Alliance thrusts you into an epic Dungeons & Dragons adventure filled with intense action, intricate puzzles and sinister intrigue, where your mastery of cold steel and devastating spells is the only thing between you and ultimate evil."
No release date is being given yet but the team did mention on Twitter that it would be "very soon".
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