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 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. All software is not the same. So do not assume that one PDF file viewer is no better than another. Two PDF viewing tools that deserve your consideration are Evince and Okular. Each offers features not found in more basic lightweight PDF viewing options.