Homepage link gets 404. LizardTech site has no mention of DjVu app, viewer, plugin. Nothing about DjVu at all that I could find, not even on their "retired products" page.

The djvu format is mainly used for scanned documents. It takes less place and is more readable that the same document scanned in tiff or pdf.

djvu documents are similar to pdf documents and tiff files. i have found that the djvu format is used on a fair amount of science-oriented sites rather than pdf or tiff. under windows the djvu plugin works very well, unfortunately, for reasons i have yet to understand, the djvu plugin only functions correctly under os x when used in conjunction with the djvu plugin host application [which is provided with the plugin bundle], this makes viewing djvu files somewhat memory and cpu intensive. if the people at lizardtech can get the plugin working on its own, without the plugin host app, this would be great, but until then i must stay away from it.

It would be nice if there was another sentence with some clue as to what a DjVu document is. The homepage isn't much help either. Some sort of PDF competitor? I really can't tell!