MapBox, the start-up behind the map function in Foursquare and car-service Uber, announced Wednesday it closed a $10 million financing round from Denver-based venture firm the Foundry Group.

The Washington- and San Francisco-based start-up customizes interactive maps for Web sites and apps. In addition to supporting smartphone technologies like Uber, MapBox’s platform is used by media outlets to visualize data for readers — for instance, Financial Times used it to create a map illustrating regional conflict in Syria. NPR, USA Today, and Slate have done similar projects on the platform.

This round of funding will be used to add more people to MapBox’s 35-member team, particularly engineers, according to chief executive Eric Gundersen.

“We’re only going to win if we have the fastest mapping technology,” Gundersen said.

The Foundry Group has invested in several data-centric start-ups including FitBit, which relies on special wrist gear and other wearable monitors to track fitness. “While the digital mapping and satellite imagery industry has long been dominated by large companies, governments, and a proprietary data mindset, the open-source and open-data movements have made inroads into the mapping world,” Foundry Group managing director Ryan McIntyre wrote in a blog post announcing the financing.

This is MapBox’s first round of early-stage financing. Until now the start-up has relied on $649,000 in grants from the Knight Foundation. Last year, MapBox won a Knight Foundation news challenge by proposing to improve OpenStreet Map, an online world-map any user can contribute to, by making it easier to add building locations, street names and points of interest.