"IMO, Active Directory is one of the best product from
Microsoft, since it's based on a well known standard like X.500
(aka LDAP) and it has a good interoperabilty (although it could be
better, see all the problems Samba people had in the past). So,
even if there are tools like PHPLdapAdmin which are pretty good, if
you need to automate users and groups management, there's nothing
better than a command line tool. Enter adtool."