PDF (Portable Document Format) is the omni-present file format for all important documents that need to travel from one place to an other. They work on every platform, so long as a reader is installed, and they aren’t editable. The key is that every PDF document comes across exactly the way the author intended it, save the infamous inconsistencies proprietary software like Microsoft Word often impose. PDF, in itself, is also proprietary, though. It’s not open. It’s just been around long enough to seem that way.
Adobe Reader (formerly known as Acrobat Reader) is the official reader software that accompanies PDF. Throughout the years, Adobe Reader has put on weight and has become increasingly bulky, and.. slow. Panning through a document containing more than a few dozen pages usually bogs down your system, peaking CPU performance along with it.
You aren’t necessarily tied to Adobe’s own reader, though. There are dozens of other, faster applications that handle PDF fine and even provide a [roughly] comparable set of features. I’m talking about Foxit Reader 2.3, in particular: A free application that incorporates nearly all of Adobe Reader’s features with gracious speed.
Foxit supports all the usual: bookmarking, commenting, magnifying, tabbed browsing, etc. And, best of all, no more panning through documents in slow motion.
Foxit Reader is available for free on Windows and Linux.