Djbdns

A DNS daemon written by Dan J Bernstein, the notoriously brilliant (and cranky) math professor of Qmail fame. Far less feature robust than BIND, and even quirkier to configure - but also much less bloated, and accordingly much faster and more secure. This makes it a constant first pick for simple but heavily trafficked nameservers. djb also wrote a special rbldns version, especially for RBL servers.

Compare and contrast: BIND, djbdns, powerdns