DjVuLibre - DjVuLibre: Open Source DjVu library and viewer
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.
RoxyApps eBook Conversion Tool - Convert djvu, epub, fb2, lit, azw, lrf and other eBook files to txt, pdf, pdb, rtf and other formats
djvu-pdf.com - Converts PDF to DjVu and DjVu to PDF online.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
DjView4 - Standalone viewer for DjVu files.