Put the World in Your Pocket with Marble

KDE's Marble breaks free of the desktop—and it knows where it's going.

Have you ever wondered what it would be like to have the whole world at your fingertips? How about cradling it in a single hand, putting it in your pocket and taking it with you wherever you go? With KDE's Marble Virtual Globe on your mobile phone, you can do just that.

Yes, you now can run Marble on a smartphone that supports Nokia's Qt framework. That could be useful, the next time you are arguing with a friend about which is farther north: London, England, or London, Canada. However, you could answer that kind of question using a mobile Web browser, or you even could use your phone to call someone and ask. At first glance, having a virtual globe on your phone seems like little more than a fun gimmick—something to play with and impress your friends. But if you look a little deeper, you will find that Marble can do much more than plug the gaps in your geography knowledge. It can help you find yourself and guide you home.

Figure 1. Marble's mobile version puts the world at your fingertips.

Navigate Freely

Marble has long been KDE's virtual globe application, providing satellite, atlas and OpenStreetMap mapping of the world. Since its 0.10 release last August, Marble has included route-finding capabilities, so you can enter two locations and have Marble calculate a route and provide step-by-step directions. However, with version 1.0, released in 2010, Marble's navigational capabilities and optimizations for mobile devices have really come of age. Combined with a suitable smartphone, this gives you a completely free navigation system—free software and free map data.

Figure 2. You easily can use a smart phone running Marble as an in-car satellite navigation device.

So, how can you use Marble to turn your phone into a personal navigational device? In principle, you can run the software on any device that supports Nokia's Qt toolkit. In practice, most testing is done on Nokia N900s running Maemo, and packages are available for this platform. Marble also will run fine on MeeGo when the first MeeGo-powered phones appear. In the view of lead developer Torsten Rahn, “It would be really cool to see Marble prepackaged for more platforms, such as Symbian, Android, WinCE and others.”

Once you have Marble installed, you just need an excuse to play with it. Imagine that your employer calls you at home one morning and wants you to to travel to a client's office a couple cities away. Over breakfast, fire up Marble on your mobile phone, enter your current location or let Marble find it using GPS, enter your destination and wait for Marble to query a range of routing services before presenting you with a set of options, the best selected by default. If you want to avoid a road you know is particularly busy in the morning, you can choose one of the alternative routes or set an additional via point to avoid it. If you need to pick up your suit from the dry cleaning shop on the way, you can add that to the route too.

When you are happy with your journey plan, just use your home wireless network to download the maps for the entire route before you hit the road. That way, you won't have to use more expensive mobile network bandwidth on the journey. Then, you can flick Marble into guidance mode, sit back in your car and watch as Marble tracks your progress along the route and provides step-by-step directions and relevant maps. While you travel, you will see that Marble displays a progress bar to warn you of the next turn (it counts down from 1,000m). You can check the icon that shows you the direction of the next turn and know that if it is grayed out, the next turn is still more than 1,000m away. Check the step-by-step text instructions for further guidance. You also get to see the overall distance to the destination and can toggle between guidance and map mode that enables you to pan and zoom the map manually. Remember also to keep your eyes on the road.

Figure 3. Marble's customized guidance mode interface shows only the information you need: the next turn and when to expect it.

You might be tempted to play with Marble's routing just for the fun of it, while racking up big mobile data bills to download all the map data. So, it's fortunate that Marble allows you to download map data for planned journeys at a convenient time, such as when you are within range of your home wireless network. According to developer Dennis Nienhüser, “Marble 1.0 allows you to download map data along the route, which keeps the download amount significantly lower if you're interested only in the route part.” This can cut data downloads by 85–90%. You even can work out routes entirely off-line. Marble can download a set of off-line maps to do vehicle routing all around the world.