This tool is no longer being developed or maintained.
ViewPDF shows PDF files, clearly indicating annotations and possible mistakes (such as spelling errors).
ViewPDF is licensed under the GNU General Public License v 2 open source license.
To build ViewPDF you will need a good C++ compiler (e.g., GCC), the Qt 4 libraries (at least Qt 4.6), the Poppler library (at least 0.18, although at least 0.20.4 is recommended), the enchant library, a spelling library for enchant to use, and at least one spelling dictionary—all these should be available as standard packages on most Linux and BSD systems. For Mac OS X you'll need to install Xcode for the compiler and then get Qt and Poppler separately. The source is viewpdf-0.6.2.tar.gz (19K; SHA1: b157da0f145119f1392c97273e097742bd00d0ee). Building follows the standard pattern for Qt 4 applications and is explained in the README; the steps are reproduced here:
If you like ViewPDF, you might like to buy one of my books. I also provide training and consultancy in C++, Qt, Python, PySide, and PyQt.