We describe the QccPack software package, an open-source collection of library routines and utility programs for quantization, compression, and coding of data. QccPack is being written to expedite data-compression research and development by providing general and reliable implementations of common compression techniques. Functionality of the current release includes entropy coding, scalar quantization, vector quantization, adaptive vector quantization, wavelet transforms and subband coding, error-correcting codes, image-processing support, and general vector-math, matrix-math, file-I/O, and error-message routines. All QccPack functionality is accessible via library calls; additionally, many utility programs provide command-line access. The QccPack software package, downloadable free of charge from the QccPack Web page, is published under the terms of the GNU General Public License and the GNU Library General Public License which guarantee source-code access and as well as allow redistribution and modification. Additionally, there exist optional modules that implement certain patented algorithms. These modules are downloadable separately and are typically issued under licenses that permit only non-commercial use.