Okular (Document Viewer)

Okular (Document Viewer) is a file viewer tool developed by KDE. This program enables users to preview and access documents or files. Supported file formats include TIFF, PDF, DjVU, XPS, CHM, and Open Document. The program can also read comic book and ebook files including ePub, Plucker, Fiction Books, and Comic Book. The program also enables users to view images with the following file formats: JPEG, PNG, and BMP.

Okular (Document Viewer) features a simple graphical user interface. Menu bar options include File, Edit, View, Go, Bookmarks, Tools, Settings, and Help. The function bar provides buttons for Previous, Next, Zoom In, Zoom Out, Selection, and Browse. The Selection tool allows users to highlight and select specific portions of the text file. Selected content may be tagged as bookmark, highlighted, or commented on.  A tabbed interface occupies the left panel. The main tabs correspond to Contents, Thumbnails, Reviews, and Bookmarks.

The Contents tab displays the parts of the document including the cover page, table of contents, if there are divisions provided. The thumbnails tab shows the general thumbnail views for the contents of a specific file. The Bookmarks tab displays the bookmarks in the file, if any had been set by the user. The right half of the window previews the contents proper of the file or document. The page selector is displayed at the bottom of the Preview window.