Abstract: We present the two-user Responsive Workbench: a projection-based virtual reality system that allows two people to simultaneously view individual stereoscopic image pairs from their own viewpoints. The system tracks the head positions of both users and computes four images - one for each eye of each person. To display the four images as two stereo pairs, we must ensure each image is correctly presented to the appropriate eye. We describe a hardware solution to this display problem as well as registration and calibration procedures. These procedures ensure that when two users point to the same location on a virtual object, their fingers will physically touch. Since the stereo pairs are independent, we have the option of displaying specialized views of the shared virtual environment to each user. We present several scenarios in which specialized views might be useful.