Without knowing why this question is being asked, I have to assume it's for a class and you want to know about looping in a program. I would not refer to these as infinte processing loops. Many programs will loop until they are requested to stop. To keep the CPU usage down, they will wait for work in the operating system but they are still essentially in a loop because once they complete the request, they loop back to the wait in the operating system. For example, you normally start Microsoft outlook and never close it. It's in a loop waiting for Emails to arrive so it can notify you. Much of the wait occurs in TCP and in Windows for mouse/keyboard actions. So the loop may not occur as much as you would think but it still loops. There are hundreds of looping programs. They provide some sort of basic functionality. Many of the obvious ones use TCP. For instance have you ever used telnet, rexec or rsh. These have a looping program listening for session requests. If you have Windows XP, then look at the SERVICES under system administration. Many of these are started and running. For example plug-and-play is an obvious one. It is waiting for new devices to be attached (e.g. USB & FIREWIRE). Look at the descriptions of these services and you will see many that are obviously monitoring for something or in a loop. In the UNIX world, these tasks are called daemons. In the MVS world, they are called started tasks.