  Distributed systems technologies supporting 3D visualization and social
collaboration will be increasing in frequency and type over time. An emerging
type of head-mounted display referred to as the head-mounted projection display
(HMPD) was recently developed that only requires ultralight optics (i.e., less
than 8 g per eye) that enables immersive multiuser, mobile augmented reality 3D
visualization, as well as remote 3D collaborations. In this paper a review of
the development of lightweight HMPD technology is provided, together with
insight into what makes this technology timely and so unique. Two novel
emerging HMPD-based technologies are then described: a teleportal HMPD(T-HMPD)
enabling face-to-face communication and visualization of shared 3D virtual
objects, and a mobile HMPD (M-HMPD) designed for outdoor wearable visualization
and communication. Finally, the use of HMPD in medical visualization and
training, as well as in infospaces, two applications developed in the ODA and
MIND labs respectively, are discussed.
