Instead of switching between apps to secure a ride during rush hour, people in China can now hail from different companies using a single app. Some of the country’s largest internet companies — including ride-hailing giant Didi itself — are placing bets on this type of aggregation service.

The nascent model is reminiscent of a feature Google Maps added in early 2017 allowing users to hail Uber, Lyft, Gett and Hailo straight from its navigation app. A few months later, AutoNavi, a maps app owned by Alibaba, debuted a similar feature in China. Other big names like Baidu, Hellobike, Meituan and Didi subsequently joined forces with third-party ride-booking services rather than building their own.

The trend underscores changes in China’s massive ride-hailing industry of 330 million users (in Chinese). The government is tightening rules around vehicle and driver accreditation, leading to a widescale driver shortage. Meanwhile, established carmakers including BMW and state-owned Shouqi are entering the fray, offering premium rides with better-trained fleet drivers, but they face an uphill battle with Didi, which gobbled up Uber China in 2016.

By corraling various ride-booking services, an aggregator can shorten wait time for users. For new ride-hailing players, riding on a billion-user platform like Meituan opens up wider user acquisition channels.

These ride-hailing marketplaces let users request rides from any number of third-party services available. At the end of the trip, users pay directly through the aggregator, which normally takes a commission of about 10%, although none of the players have disclosed how revenue is exactly divided with their mobility partners.

In comparison, a ride-hailing operator such as Didi charges about 20% from each trip since they take care of driver management, customer support and other dirty work which, to a great extent, helps build the moat around their business.

Here’s a look at who the aggregators are.