Linux based server
Installed several different Virtual OS(XP, MAC, 2000)
Each user open browser, open address: http://mydesktop (for example we will use static IP for test)
and system (in browser) open Login screen, with user name, password and account number.
When user enter all info in browser he will see his desktop, (bases on profile he create, os he chose..etc)
like VNC, just need to have access several users same time to different os
Dont need to build whole system, just a simple example( one or 2 OS) 2 user accounts.
IF any questions, let me know.