Abstract: A wearable computer system which may be used in various applications including virtual reality, augmented reality and mixed reality applications. The system may be worn by a user while using such systems and applications. Power may be supplied by a battery which powers a computer, a graphics card, a head mounted display and other peripherals. The system may include a counterbalanced configuration of the power supply and computing components through strategic placement to achieve optimal weight balance between a front portion and a rear portion of the wearable computing system, and may include a frame that allows for protection and proper ventilation for standing, seated or lying (front or back) user positions. The system may also include one or more tracking markers and/or tracking devices built or placed on the system for tracking the spatial position and orientation of the user using optical, RF, or ultrasonic tracking technologies, for example.