A, and probably the biggest, internet search engine, reachable e.g. at http://google.com
See Fuzzy Google truth for an oracle that filters out how many pages Google found for a query.
For examples of use of the "Google Web API" with Tcl, see [L1 ]. Active discussion of the API is available through google.* netnews [L2 ], as well as [L3 ].
[Anyone want to add info here about code to search google's comp.lang.tcl* newsgroups?]
CL daily uses something like
set keywords "DDE+Word"
set URL http://www.deja.com/\[ST_rn=ps]/qs.xp?ST=PS&svcclass=dnyr&firstsearch=yes&preserve=1&QRY=$keywords&defaultOp=AND&DBS=1&OP=dnquery.xp&LNG=english&subjects=&groups=comp.lang.tcl&authors=&fromdate=&todate=&showsort=score&maxhits=25
...
[Anyone want to add info here about code to convert usenet message-id strings into google URLs?]
Use http://groups.google.com/groups?as_umsgid=$message_id (replacing $message_id with the usenet message-id of the post in question).
If you check http://www.google.com/apis/api_faq.html , you will see that there is a WSDL definition for google, allowing an application using SOAP to access the host. Tcl examples appear in various places, including the intel.com publication above. Notice reliance on the Web API eliminates needs for web scraping.