The rfc954 whois protocol is extremely simple, you just send the query
string to port 43 and the server spits back the results. You can
probably adapt any finger CGI. Or you could write a one-line socket or
netcat program to do it.
It used to be you could use the gopher protocol for such generic
protocols, something like gopher:43//whois.internic.net but Netscape
at least seems to have brokwn this (rather severely, it runs winzip!)
and I don't know if this trick ever worked on IE.