Okular is a universal document viewer developed by KDE. Okular works on multiple platforms, including but not limited to Linux, Windows, Mac OS X, *BSD, etc. Features: Supported Formats: PDF, PS, Tiff, CHM, DjVu, Images, DVI, XPS, ODT, Fiction Book, Comic Book, Plucker, EPub, FaxSidebar with contents, thumbnails, reviews and bookmarksAnnotations support