Shortly after Google Maps service was introduced, independent developers have developed thousands of hybrid maps, often referred as “mashups", used to display content over Google’s interactive maps. As Google product manager Thai Tran noted on his blog there are already over 50,000 Google Maps mashups.

But creating such a hybrid maps requires some technical knowledge, therefore Google decided to step in and simply the process by developing a new set of widgets, called Mapplets.

Mapplets were mentioned by Google for the first time in May at Where 2.0, a mapping conference, after the company launched in April MyMaps service, which allows users to drop place marks onto a map to create a personalized version.

These new mini-applications are developed by Google or third-party developers and let users gather and add data from multiple sources to Google Maps. After completing all modifications, the users can save their customized maps to a personal library.

According to Google product manager Thai Tran, Mapplets were introduced in order to make it easier to users to build maps with dynamic content.

"We noticed many of these mashups simply displayed a static set of places on a map, such as the best bars in San Francisco, yet the authors had to set up a website and write JavaScript code to generate the map, which is not something that we could expect the average person to do." Tran wrote. "We also noticed that much of this great content was not getting discovered, even though millions of users were coming to Google Maps every day and searching."

How does Mapplets work? On his blog, Tran has offered a very good example. “If you're looking for a home in Chicago, you can add Mapplets that display real estate listings and Chicago Transit Authority train lines so that you can find out which homes are near public transit. To get an even richer sense of the surroundings, you could also layer in photos of the neighborhood and local events (from Zvents). When you find a home that you're interested in, simply click on "Save to My Maps" in the home's info bubble and save a copy of it to your personal map.”

Google offers already over 100 of these mini-applications, created since the company offered in May the preview version to developers. If you will access the "My Maps" tab at Google Maps, you’ll find mapplets such as those from Booking.com for hotel pricing and availability, from WeatherBug for weather or for gas prices from GasBuddy.

Google also offers its own mapplets, such as Google Real Estate Search, YouTube Mapplets, and Panoramio Mapplets which provides photos of locations from Panoramio.com.