One unexpected consequence of upgrading to Lion is that suddenly my normal DNS search domains stopped working. We use multiple VLANs at work with their own DNS sub-domains based on the environment.
This blog post is the culmination of year's effort researching and developing methods for analyzing and comparing managed DNS services
NSD is an authoritative only, high performance, simple and open source name server.
RubyDNS is a high-performance DNS server which can be easily integrated into other projects or used as a stand-alone daemon (via RExec). By default it uses rule-based pattern matching. Results can be hard-coded, computed, fetched from a remote DNS server or fetched from a local cache, depending on requirements.
Complete and usable DNS library. All widely used Resource Records are supported, including the DNSSEC types. It follows a lean and mean philosophy. If there is stuff you should know as a DNS programmer there isn't a convenience function for it. Server side and client side programming is supported, i.e. you can build servers and resolvers with it.
The ZoneCheck program performs several tests on your zone (ie: domain) to ensure that it is correctly configured and can be safely delegated, providing a certain quality to your domain