For what it is worth, regarding Binder/OpenBinder, there is some documentation here:
And waddlesplash made a copy of the code here:
And there seems to be another copy here which has maybe had some build fixes added:
I think Barrett has a point and we should at least take a look and learn some from this. It doesn’t mean we have to use the code but it does represent what the Be engineers were thinking for a new BeOS API, so it might make sense to let it influence ideas about Haiku R2.
I still think there is a lot of room for operating system innovation and Haiku could be part of that.