Building a Multiuser Media Server…Possible???

I would like to build a system for my home where at least 3 users can be using the systems resources at the same time, but doing different tasks (ie- one watching video, while another working in MS Office document, while still another listening to music). I would expect high quality services/sessions for each user regardless of the task they want to perform. IS THIS SOLUTION POSSIBLE GIVEN CURRENT TECHNOLOGY?