Basic classification of OSs (2)

the most asked questions about an OS: is it easy to learn/use ? how much software is available for it ? is (my) hardware well supported ? is it commonly used by others ? can I find help/support ? less common but important questions: is it well integrated with the network ? is it an open system or a closed one ? am I going to run it on a server or on a client (workstation) ? how much customizable is it ? if on a client, who will use it ? and for doing mainly what ?