PowerDNS

PowerDNS is a high-performance, open-source Domain Name System (DNS) server project that provides both authoritative and recursive capabilities. It comprises two main components: the PowerDNS Authoritative Server, which serves zone data for domains, and the PowerDNS Recursor, a recursive resolver used to obtain answers for clients by querying other DNS servers. Both components are primarily written in C++ and are designed to be scalable, flexible, and robust for large deployments.

A key feature of PowerDNS is its backend architecture. Zone data is not stored in the server itself but in backends such as local zone files or relational databases. Supported backends include MySQL, PostgreSQL, and SQLite, with additional backends available through plugins. This backend-driven design enables operators to store and manage zones in their existing data stores and to automate updates.

PowerDNS supports a broad set of DNS features, including DNSSEC for signing and validation, TSIG for secure updates, and RPZ (response policy zones) for policy-based responses. The Recursor provides high-performance recursive resolution and can be extended with scripting, notably Lua, to customize behavior. Management and automation are facilitated by a comprehensive API and command-line tools.

PowerDNS is distributed under the GNU General Public License and is widely used by internet service providers, hosting providers, and enterprises seeking flexible backends, strong performance, and extensive DNS features. It maintains active development with contributions from individuals and organizations, and it runs on most Unix-like systems.