Beamdog has a new blog post about Icewind Dale II, and it's lost source code.
Link - http://blog.beamdog.com/2017/07/real-talk-icewind-dale-ii-enhanced.html
Link - http://blog.beamdog.com/2017/07/real-talk-icewind-dale-ii-enhanced.html
At this time, the source code for Icewind Dale II can not be found. We’ve reached out to former developers and publishers with no luck. No one seems to know where it’s got to. Consider this our open call to fans for the code, patched or otherwise.
We’d love to complete the Infinity Engine series and bring you all the game you’ve been asking for, but to make Icewind Dale II: Enhanced Edition a possibility, having that source code, preferably patched, is needed before we can even start assessing whether the project is doable.
UPDATE: If you personally have a copy of the code, we'd love to get in touch. Please do not contact former developers and other IWD2 team members on our behalf.