gdnsd is an Authoritative-only DNS server. The initial g stands for Geographic, as gdnsd offers a plugin system for geographic (or other sorts of) balancing, redirection, and service-state-conscious failover. The plugin system can also do things like weighted address/cname records. If you don't care about these features you can ignore them :).
gdnsd is written in C using libev and pthreads with a focus on high performance, low latency service. It does not offer any form of caching or recursive service, and does not support DNSSEC. There's a strong focus on making the code efficient, lean, and resilient. The code has a decent regression testsuite with full branch coverage on the core packet parsing and generation code, and some scripted QA tools for e.g. valgrind validation, clang-analyzer, etc.
The geographically-aware features also support the EDNS Client Subnet spec from RFC 7871 for receiving more-precise network location information from intermediate shared caches.
Project site: https://gdnsd.org/
Release downloads: https://github.com/gdnsd/gdnsd/releases/
The code is hosted at Github: https://github.com/gdnsd/gdnsd/
Bug reports: https://github.com/gdnsd/gdnsd/issues
Wikified docs: https://github.com/gdnsd/gdnsd/wiki
Google Group for discussion: https://groups.google.com/forum/#!forum/gdnsd
See the INSTALL file for details on prerequisites and build procedure for working from the source tree or a source tarball.
The documentation is included in the source tree in POD format and installed as manpages and textfiles on installation.
COPYRIGHT AND LICENSING
gdnsd is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
gdnsd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with gdnsd. If not, see http://www.gnu.org/licenses/.