Canadian studio Beamdog who made the Enhanced Editions of Baldur's Gate I & II, Icewind Dale and others are currently testing a huge upgrade for Baldur's Gate: Enhanced Edition.
While still using the classic Infinity Engine, Beamdog went through it and upgraded a great many parts for the original release of the Enhanced Editions and it's clearly a labour of love as they continue to fix and tweak them many years after release. They recently announced a huge 2.6 game engine upgrade which will affect all three named titles, and now they're looking for more people to jump in and test.
To be clear, they confirmed that currently only Baldur's Gate: Enhanced Edition is ready for testing but since the update notes fixes for all of them it's likely the other two mentioned above will follow along after.
You can see the rather long list of updates and fixes over here. To participate you need a copy of Baldur's Gate: Enhanced Edition on Steam, and then right click -> go to Properties and find the "road_to_2.6" option. Here's some highlights of what you can expect:
- Changed to 64 bit executables; 32 bit operating systems are no longer supported
- Hundreds of bug fixes including many spell fixes
- Improved pathfinding
- Improved multiplayer stability
- Added Adventurers of Neverwinter content to all games
The list of improvements just for BG:EE is quite long too, with over 60 items just for this game being either bug fixes or general game improvements. Plenty more when counting updates that affect all three titles too it's a really impressive amount of work that's gone into the 2.6 upgrade.
If you do test it, they want your feedback to ensure it works including launching it and saving plus loading without any blocking issues. You can either leave a comment on their official forum post or on this Steam announcement post. Once ready, it will be up on the GOG store as usual too.