What good Active Directory + Exchange competition is there?

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.


Solution 1:

As far as Directory Services go, you've allready mentioned the main competitor to AD, Open LDAP. A couple more I know of are:

  • Red Hat Directory Services and its Fedora Alternative
  • Apache Directory
  • Apple Open Directory

As far as Exchange alternatives go, you might want to look at this question but some of the most popular are:

  • Zimbra
  • Open-Xchange
  • Kerio Mail Server

Solution 2:

NetWare may have disappeared (almost), but eDirectory and GroupWise are still very much around, and will run quite happily on either Server 200* or Linux.

Solution 3:

OES2 from Novell is the replacement for Netware, and it maintains the NSS filesystem on Linux (SLES Specifically) that has excellent ACL and inheritance abilities.

eDirectory is a good competitor to Active Directory for directory services.