Regarding which XML parser to use: I would suggest sticking to nsxml. Reasons:
- it's based on libxml that seems to be actively maintained and quickly evolving (they have some support for XSLT already)
- I believe it already has enough functionality for OpenACS needs and improving it would be rather easy
- it's true that aD is probably going to stop developement but the source code is there and increased usage (in OpenACS) will increase the chances that someone will pick it up. This would benefit not only OpenACS but the whole AOLserver community since so far there is no fast and comprehensive support for XML in it.
