FAQ: Other Questions

Q: What software does the Great Circle Mapper use?

A: The Great Circle Mapper uses primarily custom software, with several third-party libraries and data from many sources. Please see the credits page for details.

Q: Why not use Google Maps?

A: Using Google Maps would add some features, notably the ability to pan, but would have a number of downsides:

The site would be slower. In addition to reducing the utility of the site for experimentation, the speed difference would make it especially painful with slow network links (like smart phones when not using WiFi).
Fewer browsers would work. Google Maps depends on JavaScript and other browser features. The Great Circle Mapper is designed to work with any graphical browser, though appearance and some features may degrade with less capable browsers or without JavaScript.
A choice of map projections (such as orthographic maps, including the polar aspects) would not be available with Google Maps.
Non-web ports of the site would not be possible.
Simplicity and independence from other sites helps make the Great Circle Mapper more reliable.

Google Maps is a great site but considering the tradeoffs and after much testing, homegrown maps were selected as the best solution for building the fast, reliable site that Great Circle Mapper users have come to expect.

Q: Can I get the source code for the Great Circle Mapper?

A: No, there are no plans to release the source code.

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 so long as you do not profit from them and you include the following credit on pages which include maps:

Maps generated by the Great Circle Mapper - copyright © Karl L. Swartz.

Adding the following HTML to your page will accomplish this:

Maps generated by the <a href="http://www.gcmap.com/">Great Circle Mapper</a> - copyright © <a href="http://www.kls2.com/~karl/">Karl L. Swartz</a>.

The following variation may also be used, replacing YOUR NAME with your name or your organization's name as appropriate:

Maps generated by YOUR NAME using the Great Circle Mapper - copyright © Karl L. Swartz.

This permission may be altered or rescinded at any time and for any reason.

Please embed your maps directly from www.gcmap.com rather than saving the image—the server can easily handle the load—and make the map a link to the URL used to generate it, which allows your readers to experiment with your map. In other words, if you want to include a Blue Marble map of SFO-LHR, your HTML should look like

<a href="http://www.gcmap.com/mapui?P=SFO-LHR&MS=bm"><img src="http://www.gcmap.com/map?P=SFO-LHR&MS=bm"></a>

I'd appreciate it if you would e-mail me a brief note about your use of Great Circle Mapper maps including the URL of your site. If you'd like me to include a pointer on the Links or Blogs page, as appropriate, please let me know how you'd like it to read. (This does not represent a guarantee that a link to your site will be added to any Great Circle Mapper page.)

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 under the same terms of use as for your own web page.

Q: May I use the Great Circle Mapper's maps on my commercial site?

A: Please write to Karl L. Swartz regarding terms for commercial use of the maps.

Q: How can I buy advertising on the Great Circle Mapper?

A: Advertising will be offered on the site soon. Please check back for details.

Q: What browsers does the Great Circle Mapper work with?

A: The Great Circle Mapper is intended to support all standards-compliant web browsers. It has been tested with the following browsers:

Camino 2.0 (Mac OS X)
Chrome 3.0 (Mac OS X)
Firefox 3.5 (Windows/XP, Mac OS X)
Firefox 3.6 (Windows/XP, Mac OS X)
Internet Explorer 6 (Windows/XP)
Internet Explorer 8 (Windows/XP)
Safari (iPhone)
Safari 4 (Mac OS X)

There are known problems with Internet Explorer (IE) due to non-compliance with web standards. In IE 6, the map scaling widget is not visible. This problem does not occur in IE 8 though a few minor cosmetic issues remain. IE 7 is believed to display like IE 8 but this has not yet been tested. A fix for the IE 6 problem will be implemented as soon as possible.

Q: How many points/paths can be on a map?

A: See answer here.

Q: I found a bug in the Great Circle Mapper. How can I report it?

A: Please e-mail the following data:

The URL at which the problem occurred.
A description of the problem.
The name of browser you were using and its version.

A screen image is rarely necessary or helpful so please do not include it.

Q: Does the Great Circle Mapper have a Facebook page?

A: Yes, please see the Great Circle Mapper on Facebook.

Q: Is the Great Circle Mapper on Twitter?

A: Yes, at Great Circle Mapper (gcmap) on Twitter.

Q: How can I make a donation to help keep the site going?

A: You may make a donation using PayPal.

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