There, one can read

Q: May I use the Great Circle Mapper's maps on my web page?
A: You may use maps generated by the Great Circle Mapper on non-commercial web pages[...]

Q: May I use the Great Circle Mapper's maps on Wikipedia?
A: You may use maps generated by the Great Circle Mapper on Wikipedia so long as you

Provide attribution to the Great Circle Mapper Include a link to this FAQ entry List the source as the URL used to generate the map, which allows readers to experiment with your map.

For example, the following Wikipedia markup would meet these requirements for a Blue Marble map of SFO-LHR:

== Summary == {{Information |Description = Map of SFO-LHR |Source = http://www.gcmap.com/mapui?P=SFO-LHR&MS=bm |Author = [http://www.gcmap.com/ Great Circle Mapper] |Permission = http://www.gcmap.com/faq/using#wikipedia }} == Licensing == {{Attribution||[http://www.gcmap.com/ Great Circle Mapper]}}

The IP owner has all rights to grant or deny the access to their works for any and all purposes and under any and all prerequisites (even absurd ones like in the Beerware license - accepted on Commons! - or asking e.g. for that an individual who wants to use some intellectual property makes a handstand and barks to the full moon before using the stuff commercially. That's the principle of en:freedom of contract).