xip-pdns
This is the source of the PowerDNS pipe backend adapter powering xip.io.
Install this on your system, adjust etc/xip-pdns.conf to your liking, and configure PowerDNS as follows:
launch=pipe
pipe-command=/path/to/xip-pdns/bin/xip-pdns /path/to/xip-pdns/etc/xip-pdns.conf