Zathura is a lightweight viewer for pdf which works on plugins. Here is shor description :
Zathura is a highly configurable and functional PDF viewer based on the Poppler
rendering library and the GTK+ toolkit. The idea behind zathura is an
application that provides a minimalist and space saving interface as well as
an easy usage that mainly focuses on keyboard interaction.
But the viewer will not work unless you install the plugins to display the correct plugin.