vpsAdmin is a Web-based admin panel with support for multiple OpenVZ servers and division between frontend and backend.
MyANT DNS is a Web frontend for BIND DLZ that expands upon the original ANT DNS that uses MySQL.
VDnsAdm is a Web-based management GUI for nameservers running PowerDNS with a MySQL backend.
GNU grep, egrep and fgrep.
A network protocol analyzer for Mac OS X.