libggpk is a C++ library for extracting information from the ggpk archive used in the game Path of Exile by Grinding Gear Games. Path of Exile is an excellent free-to-play action RPG available at http://www.pathofexile.com/ and you should definitely check it out.
This software DOES NOT modify the game or the data used by the game in any way. It is intended for educational use only.
libggpk uses the Qt4 library to read large files (64-bit file offsets) in a cross-platform way. The Qt library is available at http://qt.nokia.com/downloads
Most of what you probably want to accomplish can be done by using the 'ggpk' utility included in tools/ggpk -- this is a command line program that can extract files from the archive, list all files contained in the archive, or print information about the files contained in the archive.
libggpk is licensed under the MIT license, the text of which is located within the LICENSE file that should be included with this source distribution.