Loops MNG has a simple loop structure that can be used for repeating images. In addition to the simple single-image frames described thus far, MNG can also describe composite images that are built up of two or more PNG images. For example, one image could be a full-screen background while others could be small sprites that are moved around by means of the LOCA chunk. Such viewers can take advantage of hardware acceleration if present. All images are initially invisible and are made visible with explicit directives.
All images are initially invisible and are made visible one at a time, like cards being dealt.
The MNG format specification has not yet been frozen, but it has reached a state where test implementations are possible. There has been discussion of MNG since the completion of the PNG design in March 1995, and the first informal MNG drafts appeared on June 25, 1996. These have already been used by the U.S. Army for real presentation work. Glenn has been involved in computer graphics for 30 years, is one of the developers of the PNG format, and is leading the MNG development effort.