Bluebeam Revu

Bluebeam is the manufacturer of Revu, a PDF creation, markup, and editing tool for Windows and tablets, and now including support for Mac.

Revu comes in three forms: Standard Edition, CAD Edition, and eXtreme Edition. The following link provides a comparison of the features of each: http://www.bluebeam.com/us/products/revu/compare.asp

Bluebeam also includes Collaboration tools to share work with your design team, and Vu, a view-only tool.