Suggestions

[aceres]

Well, you could use Adobe Flash. There's an AS3 Zip class but it doesn't support folders inside the zip, perhaps there's another one that supports folders. This can be used to extract any resources inside. You could also have a treeview object to show contents of the zip and user could select objects or images to view on their own.

Then using Away3D you could display 3D objects and even animations if present. However supporting various formats won't be easy. Besides many 3D formats, you have image formats like TGA or DDS which may lack classes for them to be opened in Flash.

Another useful thing would be the ability to get the already downloaded zip from Flash so that it won't have to be downloaded again.