Based on this question regarding enhanced permission support in filesystems, what is the best permissions + directory and mail stack to compare against Active Directory on NTFS with Exchange?
I'm familiar with OpenLDAP for directory services, and Scalix for email and calendaring. Are there other good competitors in this arena? Novell's NetWare would have been my answer a decade ago, but with that having pretty much disappeared, I haven't seen a good replacement, outside of "perl-and-duct-tape".
ie - is there an integrated packaging of these (or other) toolsets?
The thrust of this question is to see how plausible a completely AD-free environment is, with a quality calendar, email, and directory services functionality.
It can run on Mac OS X, Linux, or Windows - I'm just very interested to see what others have done/seen/used in this area.