Uber is growing on an unprecedented scale. To be able to keep up, its largest rivals across the world have teamed up to provide cross-platform service to their users. Lyft in the US, Didi Kuaidi in China, Ola in India, and GrabTaxi in Southeast Asia have now formalized their strategic partnership with each other.

Long story short, their agreement means customers of each company will be able to use their local apps even when they travel to other markets in the network starting in Q1 of 2016. Each country is in charge of “mapping, routing and payments through a secure API.”

All four companies will maintain their independence from each other and will be regionally-focused. This is the path they would like to take and their alliance should not be viewed as a precursor to a merger.

“We’re not excluding expansion to other places, but we are a startup and cautious about how we grow,” a spokesperson for Didi Kuaidi told TechCrunch. “The idea is not to merge and acquire but to find people we can work with. In China we have an urban population of 800 million but we are only currently serving 250 million, so we have a lot of room to grow, and this population will always be our priority.”

The four-way alliance all started when Didi first invested in Lyft for $100 million last September, $350 million in GrabTaxi last August, and part of a $500 million megaround for Ola sometime in the summer.

Uber, for its part, is taking on a different approach and is aggressively entering markets like China by taking on current ridesharing leaders. Lyft, for example, prefers a softer approach and would familiarize themselves with the market first before expanding.

The unified front against Uber is well-within reason. Uber has already accumulated funding totaling $8.21 billion and is looking to raise another $2.1 billion.