a free (under GNU Lesser GPL) library which provides a uniform interface to a large number of hash algorithms. These algorithms can be used to compute checksums, message digests, and other signatures.
a free library providing windowing and widgets for graphics APIs / engines where such functionality is not natively available, or severely lacking. The library is object orientated, written in C++, and targeted at games developers who should be spending t
C++ interface for the popular GUI library GTK+. Highlights include typesafe callbacks, widgets extensible via inheritance and a comprehensive set of widgets.
a high-level audio API. It can play Ogg Vorbis, MP3, FLAC, uncompressed WAV, AIFF, MOD, S3M, XM, and IT files. For audio output, Audiere supports DirectSound or WinMM in Windows, OSS on Linux and Cygwin, and SGI AL on IRIX
The Typesafe Callback Framework for C++. allows you to define signals and to connect those signals to any callback function, either global or a member function, regardless of whether it is static or virtual.
a C library for reading and writing sound files such as AIFF, AU, WAV, and others through one standard interface. It can currently read/write 8, 16, 24 and 32-bit PCM files as well as 32 and 64-bit floating point WAV files and a number of compressed formats.