Documents stored as PDF ("Portable Document Format") files require a special viewer in order to open them. The
creator of the PDF format, Adobe Systems, offers their free Adobe Reader software:
♦ Adobe Reader
(for Windows, MacOS, Linux, mobile devices, and more)
There are other free software options that can be used to view PDF files. Their features are not as complete as
those of Adobe Reader, and they may not be able to properly display everything in a complex PDF file created by
the most recent versions of Adobe's PDF creation software, but they are much smaller in size and can usually be
run from portable devices such as USB flash drives:
