Aftershock is an open-source (MIT licensed) Gopher server. It was developed with J2SE 1.4, and is based in part on the Soma web server.
News: Aftershock 1.0.1 released.
The first release version of Aftershock has been released. You can download aftershock-1.01.tar.gz now. The manual and README are also available on this site.