Heliodisplay

"Heliodisplay images are not holographic although they are free-space, employing a rear projection system in which images are captured onto a nearly invisible plane of transformed air. What the viewer sees is floating mid-air image or video. These projected images and video are two-dimensional, (i.e. planar) but appear 3D since there is no physical depth reference. While conventional displays have the benefit of being attached to a physical substrate, Heliodisplay projections are suspended in air, so you will notice some waviness to the quality of the projections." (Source: Bravenet.com)