katarakt is a simple PDF viewer. It is designed to use as much available
screen space as possible.
There are currently two layouts. The presentation layout is very simple and
only supports scrolling on a per page basis. As the name suggests the
current page is displayed in the center and zoomed to fit the window. It is
active by default.
The grid layout is much more advanced and offers continuous (smooth, per
pixel) scrolling, zooming and adjusting the column count. Pages keep their
correct relative size and are shown in a grid.