Verisign has been granted a patent protecting the lookup of domain names. The patent protects the act of performing several look-ups at once, or "performing a multitude of searches simultaneously, transparent to the user.
"Specifically, the improved query server searches for an existing domain name records in various domains and then displays the results in a formatted manner, thus eliminating the need for a user to perform individual searches."
It would appear that a simple shell script that searches for theregister.com, .org or .net would fall foul of the "invention", which Verisign filed in 1998. The illustration implementation listed in the patent describes a Perl script that forks. In this discussion of the patent at ICANNwatch, Karl Auerbach points out that UNIX resolvers have been doing this since the mid 1980s.
Through its Network Solutions Inc. subsidiary, Verisign runs the lucrative .com and .net registries. ®