"Okular and Evince are two excellent, versatile PDF viewers for
the Linux platform. The big difference between the two rests in the
interface. Evince has a much simpler design. Okular is more focused
on a graphical view. If all you do is view documents, then either
of these two programs will serve your needs well. However, if you
need to add notes for presentations or collaborative projects,
Evince comes up a bit short.
"One of the hallmarks of using the Linux operating system is the
ability to choose. The choices do not end with opting not to use
Microsoft (Nasdaq: MSFT) Windows or Mac OS X and instead choosing
from among dozens of Linux distros. You also get the freedom to
decide which individual software tools and applications are the
best fit for your daily routine."