I am reposting (reopening for discussion/answers) here my closed questionOpen source alternatives to MS AD features (but) installable on MS Windows (closed as subjective and argumentative) Note that I am banned from my questions in serverfault.com (and its affiliates).I found afterwards that the given "in-topic" ((except direct insults and off-topic posts nourished there by "moderators" and "community")) answers were misinformation, since there are such alternatives both non-MS:http://web.mit.edu/Kerberos/dist/ (MIT Kerberos for Windows)http://www.userbooster.de/en/download/openldap-for-windows.aspx (OpenLDAP for Windows)as well as "free" MS add-ons for Windows XP:Active Directory Application Mode (ADAM)Please do not post in cited boards (serverfault.com, stackoverflow.com, superuser.com) where I am banned from my own previous contributions without any previous notice or any sane explanation afterwards1 person needs an answerI do too