Yes, you can.
They cannot use the same computer in the same time, only if it runs a multiuser operating system (unix).
At the moment no.
Yes, running an anti-spyware and anti-malware programs at the same time won't conflict with each other.
Very true - the X-windows graphical interface was not available in Unix systems for a long time after Unix was available.
Very true - the X-windows graphical interface was not available in Unix systems for a long time after Unix was available.
Machine-independence: The System hides the machine architecture from the user, making it easier to write applications that can run on micros, mins and mainframes. Multi-User Operations: UNIX is a multi-user system designed to support a group of users simultaneously. The system allows for the sharing of processing power and peripheral resources, white at the same time providing excellent security features. Hierarchical File System: UNIX uses a hierarchile file structure to store information. This structure has the maximum flexibility in grouping information in a way that reflects its natural state. It allows for easy maintenance and efficient implementation. UNIX shell: UNIX has a simple user interface called the shell that has the power to provide the services that the user wants. It protects the user from having to know the intricate hardware details. Pipes and Filters: UNIX has facilities called Pipes and Filters which permit the user to create complex programs from simple programs. Utilities: UNIX has over 200 utility programs for various functions. New utilities can be built effortlessly by combining existing utilities. Software Development Tools: UNIX offers an excellent variety of tools for software development for all phases, from program editing to maintenance of software.
Halo works but I'm not sure of others.
Yes, it will. Using two antivirus programs at the same time will cause conflicts, bad behavior and might corrupt files.
It would take a very long time to learn all of the Unix commands, and frankly, that isn't necessary. Most Unix users have a subset of commands they use all the time, and that is how they learn them.
One example of a time-sharing system is the bank's bankcard system, which allows hundreds of people to access the same program on the mainframe at the same time. The Multics & Unix operating systems are time sharing Operating Systems
Some versions of Unix are oriented towards real time applications, and processes in Unix can be "promoted" to real time status if desired. Other than that, you would have to define more precisely what you mean by real time for an operating system.
I think that there is only four playrers on one Xbox 360 console playing Halo: Reach at the same time, the same as any other Halo game. Hope it helped!