1 - Portable Document Format - Wikipedia, the free encyclopedia - 
PDF is used for representing two-dimensional documents in a manner independent ... Formerly a proprietary format, PDF was officially released as an open standard ...
http://en.wikipedia.org/wiki/Portable_Document_Format -

2 - Adobe Reader - 
Official site for Adobe Reader software that allows users to create and view Adobe Portable Document Format (PDF) files.
http://www.adobe.com/products/acrobat/readermain.html -

3 - Adobe - Adobe Reader download - All versions - 
... when converting or transforming PDF files into other file ... What is Adobe PDF? Careers. Online Privacy Policy. Terms of Use. Contact us. Accessibility ...
http://get.adobe.com/reader/otherversions/ -

4 - 826 - 
Offers a free PDF creation tool. Convert to PDF from any application, create and secure PDF files from Word, Excel, and hundreds of file types. PDF output with no ...
http://www.primopdf.com/ -

5 - PDF995 - 
Offers free and premium software to create, edit, and secure professional quality PDF documents from any application with no watermark.
http://www.pdf995.com/ -

6 - Adobe - Adobe Acrobat family: Adobe Portable Document Format - 
Now an open standard ? PDF is now a formal open standard known as ISO 32000. ... PDF Technology Center on Adobe Developer Connection ... PDF Library SDK ...
http://www.adobe.com/products/acrobat/adobepdf.html -

7 - Planet PDF - 
Provides Adobe Acrobat and PDF articles, tips, tricks, FAQs, and more.
http://www.planetpdf.com/ -

8 - PDFzone.com - 
Online hub to all things Acrobat and PDF.
http://www.pdfzone.com/ -

9 - Parkinson's Disease Foundation - 
PDF is working for the nearly one million people in the US who live with ... PDF Research Initiatives. Results. Apply for Grant Funding ...
http://www.pdf.org/ -

10 - PDF Solutions - 
Provider of infrastructure technologies and services that improve the yield and performance of integrated circuits.
http://www.pdf.com/ -