I have encountered this problem when I was trying to help my friend who want to learn iOS programming but at the moment cant afford to buy a Mac. I have Macbook and Mac mini.
I was avid use of linux in my past and I have used XSessions on linux where I was exploiting multiuser service from a linux machine and had my personal GUI or XSession.
As Mac is basically unix based system.
I am wondering if it is possible that I can setup my Mac mini such a way that my friend can connect to his personal xSession over the internet to my mac mini and start coding on my Mac mini.