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Dioretsa is a pdf viewer that manages pdf files with tabs (Tabbed PDF Viewer).

Basic Functions
When you click a tab, Dioretsa shows contents of PDF document corresponding to the tab.
If you select another tab when you have read PDF document and select that tab again,
you can read PDF document from the page you read last.
Moreover you can select PDF(tab) from tab-list, search a word in PDF document from search box, and speech selected text.

Other Functions
It is available to show plural windows and combine tabs in all windows to one window. (Picture 1)

You can preview PDF pages as thumbnail images and move to selected page. It is also available to resize thumbnails with lower-left slider. (Picture 2)

It is available to jump to the selected number page and rotate PDF pages. (Picture 3)

You can set up preferences below. (Picture 4)
• Hide windows when application is on deactive.
• Hide toolbar automatically in full screen mode.
• Open PDF in background tab.
• Circurate tab movement.
• Outline has priority over thumbnail view.
• Show thumbnails(outline) automatically when PDF document opened.
• Select how to show thumbnail(outline) : Drawer or Split View.
• Fit PDF automatically
• Set up default setting of how to show PDF : Single Page, Single Page(continuous), Two Page, and Two Page(continuous)

You can view PDF in full screen. (Picture 5)
(Dioretsa keeps up with Full Screen Applications of OS X Lion)
It is available to show selected page in left view (Lock Page) and view other pages in center view at the same time. You can with this function view the graph in left view while reading explanation in center view for example.
Moreover you can do "Page Lock" and "Unlock Page" from menu bar or right click menu on center view.