It is quite useless, when no program supports it. APNG could be a good replacement for it. What do you think?
Someone must use MNG for something, I implemented it in response to a request on the wishlist page. Several apps on my system use it, GIMP, all of KDE for eg.
Does libpng support APNG or is there some other library we could use for it? I guess APNG means animated PNG? Who invented that and why - we already had MNG?
Edit:
Looking at the wikipedia page, APNG seems in a kinda dubious state. There is only a patch against libpng, the PNG group doesn’t like APNG and will not add the APNG extensions to PNG or libpng. IE doesn’t seem to support it either.
I don’t think we can support it until there is at least a library for reading and creating APNG files.
Really Gimp supports MNG ? I think gimp dropped the support of MNG long ago, because mng is a dead horse. What other apps do support mng? Could you elaborate? Could you test gimp on your computer, if it still supports mng?
Firefox has support for apng since 3.0.1. In my opinion it is much better than mng. Mng did not work really good before, and i don’t know how the PNG-group want to fix that.
The Internet Explorer has support for PNG. I don’t care, if microsoft won’t implement apng, because then this only means, that microsoft lets his customers out in the cold, when all users of firefox can enjoy animated png’s. 
Does IE support mng???
In any case, why drop support for mng? if it is rather used it is ok, there is nothing bad on that. If apng is better let’s include it but don’t deprecate one in favor of other. It is like deprecate ppm because png already exists and is more used or vice versa.
Let’s have both! 
-G
Okay, we could drop support of mng at a later time, when it is evident to everyone that mng is dead. Fine.
Hooray APNG!