On Wednesday, Github announced that maps would be “diffable”—a silly-sounding term that means much in the world of Github. It’s a small and even long-expected feature, but an important one, and one that aids Github’s role in the emerging ecosystem around open data.

First, a gloss on some terms. Github is a San Fransisco-based startup whose main product—also called Github—helps developers manage different versions of a project’s code. Many developers already use a piece of software on their computer called git to manage versions of code, and Github gives them a place to store Git’s files in the cloud and collaborate with others about them. It also provides messaging functions that sometimes supplant company email.

While it costs money to host a project on Github privately, the company provides free hosting to any open-source project. If you make your code public, hosting on Github is free.

Github, then, already plays a happy home to code projects. In the past year, it’s tried to make itself friendlier and more useful for projects that use open data.

Open data, meanwhile—the effort to make information already produced by the government available to the public—is a bigger and bigger deal. Late last year, the Knight Foundation gave $250,000 to explore the creation of a U.S. Open Data Institute, an organization centered around freeing data and making it easier for people to use. Freeing, for instance, municipal restaurant health code data will allow local review apps like Yelp to display it.