It would be nice if the Linux installation could use Active Directory for authentication. I was told by support that the limitation is mono. It appears that mono has supported this for 6 years now!!!!
http://monox.mono-software.com/blog/post/mono/92/MonoX-Active-Directory-integration/
They could *also* use mono's Novel based LDAP implementation for AD authentication with a lot less effort than making their own windows client/proxy .. I've resigned myself to the idea that they aren't doing it because it's simply not a priority for them :( much to the disappointment of quite a few of us.
Adding my voice here... We chose On-Prem on Linux to avoid the extra cost of windows license. There is all kinds of LDAP support on linux
What about putting the part of the AD integration into a Windows Guest Client that runs on a machine (running 24x7) inside the AD. The SC server on linux would be able to get/sync the AD information through the guest client.
Even cloud instances could use this way to get AD integration.