Kevin writes: "A new version [1] of YAZ [2] has been released. YAZ is a C/C++ programmer's toolkit supporting the development of Z39.50v3 clients and servers. A sample client, a sample server, and documentation are included in the distribution. YAZ also includes experimental support for the industry standard ZOOM API for Z39.50. There are several changes [3] from the last version (mostly bug fixes)."
Links:
[1] http://ftp.indexdata.dk/pub/yaz/yaz-1.8.7.tar.gz
[2] http://www.indexdata.dk/yaz/
[3] http://www.indexdata.dk/yaz/CHANGELOG