libPGF is an implementation of the Progressive Graphics File (PGF)
File type detector library
PDF Library for Developers
A cross-platform XML/CSS based eBook reader
A C++/Qt ZIP library
A set of tools and libraries to help with writing eBooks
ZET-JSON is C++ library for json format.
A library to convert between braille and MathML
Open-DIS implements the IEEE DIS protocol in multiple languages.
Another C++ based JSON Library (/w Parser/Generator/Navigator)