I've tried to merge 3.3.1+ad13 with 3.4 recently for one aD project. The problem with vanilla AOLserver before 3.4 was that it didn't handle anything but ASCII properly. aD patches addressed that problem. Then there was something in 3.4 which tried to do something about this, but aD patches looked better. And they were adding Tcl functions, so there was some probability that ACS depended on that.
Anyway, I ended up with merging all 3.4 improvements except the ones which had anything to do with charsets. Somebody else added some things to ns_xml, but I don't know the details. The whole thing has been working fine in production for some time.
I've looked into 3.4.2 changelog a few days ago and the difference between 3.4 was just a few small things which can be merged without problems.
The thing I didn't do and which should be done is merging fixes from more recent Tcl releases (the one in AOLserver is 8.3.2). I've looked in the Tcl ChangeLog and it seemed worthwile to have those fixes, but I didn't have the time.
