Some Recommended PDF Readers....

The Portable Document Format (PDF) is a popular format to publish formatted text and documents.  There are several different versions of it, some qualifying as an Open Standard, some certified by ISO and some encumbered by software patents. You might want to promote the versions that are Open Standards, because Open Standards guarantee interoperability, competition and choice.  There are many programs to read and write PDF documents.  All of the PDF readers in the following list are Free Software, respecting your basic four freedoms to use, study, share and improve them.

Adobe PDF Reader Adobe Reader software is the global standard for electronic document sharing.  It is
the only PDF file viewer that can open and interact with all PDF documents.
Foxit PDF Reader


Foxit Reader for Windows is a small and fast PDF viewer that currently has over
50 million users all around the world. It lists all attached files in the PDF document,
and provides a number of common options that helps users manage the attachments, such as opening, deleting and adding description to the attachments. Users can also change the security settings when opening an attachment in this panel. 
MuPDF Reader

MuPDF is a lightweight PDF viewer tailored for high quality anti-aliased graphics. MuPDF renders text with metrics and spacing accurate to within fractions of a pixel for the highest fidelity in reproducing the look of a printed page on screen. MuPDF has a small footprint.
Okular PDF Reader Okular is a free universal document viewer based on KPDF for KDE 4.  Its
development began as part of Google's Summer of Code program.

Sumatra PDF Reader

 Sumatra PDF is a slim, free, open-source PDF viewer for Windows.  It's small
and starts up very fast.  It's designed for portable use: it's just one file with no
external dependencies so you can easily run it from an external drive. 

For a consolidated listing of PDF software that includes links to articles on computer software used to manage PDF documents, follow this link: http://en.wikipedia.org/wiki/List_of_PDF_software

For a listing of PDF software that is freeware, follow this link: http://www.hsinlin.com/software/pdf.html