Real estate site Zillow today announced that it has acquired Retsly, a Vancouver, B.C.-based startup that helps developers access real-estate data from multiple listing services (MLS). The service takes the data from these sites and normalizes it so developers can more easily use the data in their own applications. The financial details of the acquisition were not disclosed.

MLSs are the central hub for real estate data in the U.S., but they are also very insular. Every region has its own and in total, there are about 1,000 different systems. That wouldn’t be a huge problem if this were just about geographic distribution, but all of these MLSs use different software and often describe homes in different terms.

Retsly was founded in 2013 by Kyle Campbell and Joshua Lopour, who I first met at the Grow conference in Vancouver last year (Growlabs also incubated the service). Few people know more about the state of MLSs in the U.S. than these two Canadians, and Retsly was actually responsible for holding the first real estate hackathon at the National Association of Realtors conference in 2013. Given that the MLSs have generally been extremely protective of their data and the real estate business is somewhat suspicious of technology, that was quite an achievement by itself.

As Zillow’s Chief Revenue Officer Greg Schwartz to me, though, it’s worth noting that the data the MLSs provide to Retsly is only to be used by applications that were authorized by the MLS for use in the specific market the MLS covers. They get to decide how the data is used.

In addition to its service for developers, Retsly also provides MLSs with tools to manage software applications in their market and ensure that their content is being used appropriately.

“Retsly’s team and cutting-edge technology is a great fit with Zillow and aligns with our goal to offer great value and services to our industry partners,” said Zillow CEO Spencer Rascoff in a statement today. “We’re thrilled to welcome Retsly to Zillow.”

The service will continue to function as usual and Lopour says the acquisition will help the company to accelerate “the growth of a vibrant software community within the industry.”

Schwartz tells me that he believes Retsly is a great fit for Zillow. “This is an extension of our efforts to provide productivity tools to help MLSs, brokers, franchisors, teams and agents be more productive and successful,” he said. At the same time, though, he also believes that this acquisition goes a bit further than some of Zillow’s previous ones in that it provides developers with the data to create new applications and that it gives the MLSs the ability to mange that data. “We believe that when the real estate ecosystem thrives, Zillow also benefits,” Schwartz said.