Free software that lets you view, print, search, and share Adobe Portable Document Format (PDF) files more securely using a variety of platforms and devices.

Create PDF documents on the fly — for Free!     CutePDF Writer
Portable Document Format (PDF) is the standard for the secure and reliable distribution and exchange of electronic documents and forms around the world. 
This is a great tool to use when sharing downloadable  information on your website for visitors or clients giving them the ability to view documentation without altering the information in anyway. This  is also a great way to send  documentation by email to clients or friends/family that can be view by everyone and not worrying about specific software it was written in.