DjVu is a web-centric format and software platform for distributing
documents and images. DjVu was originally developped at AT&T
Labs-Research. In March 2000, AT&T sold DjVu to LizardTech Inc. who
now distributes Windows/Mac plug-ins, and commercial encoders (mostly
on Windows)

The LizardTech released the reference implementation of DjVu under
the GNU GPL in October 2000. DjVuLibre (which means free DjVu), is
an enhanced version of that code maintained by the original inventors
of DjVu. It is compatible with version 3.5 of the LizardTech DjVu
software suite.

WWW: http://djvulibre.djvuzone.org/