Quote - OnT: I guess it is not by chance, that RSR just happens to be obsolete with the same version of poser which has it's library implemented in flash. I am not familiar with flash, but since it is mainly used to realize blinking web-buttons, it is probably considerably easier to display png-images than any other old format.

That's an interesting logic, so you mean that Poser Pro Pack and later loaded and displayed the RSRs and converted them to PNG just for fun? And if the RSRs were deleted, they created RSRs from the PNGs internally to display those RSRs? ;-)

Btw: Poser still does all the important work, the Flash library just displays the results of that work...

Quote - As far as i know there is no format description for RSR available, so even the third-party tools cannot easily support it. Not even ImageMagick, which otherwise supports any image format regardless how rare it was :-(

RSR is no image format. It's a container format. It's so old that it's hard to find information about it, but I found what I needed on the web a few years ago...