While a lot of people have likely moved onto the newer editions of games like Baldur's Gate and Icewind Dale, GemRB [Official Site] is still being updated if you wish to play the originals on Linux.
The latest version, v0.8.5, was released this month bringing in some major changes thanks to SDL2, here's the highlights of what's changed:
- SDL2 resolution-independent window scaling, environmental audio, IRIX compatibility
- regeneration during sleep, time dilation
- iwd2 ability stacking, iwd ZZ* weapon bonuses
- portrait.2da handling, avatar shadows, dialogF.tlk handling
- better compatibility with bgt, 10pp, ia, kelsey, dr
- sdl2 input, mouse scrolling, opengl driver
- iwd2 cg&lu, item (un)usability, avatar sizes, permanent clabs
- ambients, verbal constants, random walk, walk sounds
If you're interested in helping development, they have a todo list here of what is still to be done. Even though it's not technically finished, a number of games can be played through to completion like Baldur's Gate I&II and Icewind Dale.
Thanks for the tip mcphail.