China's biggest search engine—Baidu—and Microsoft are expanding their self-driving-vehicle partnership to cover data storage, security, and artificial intelligence services for the companies' open-source autonomous vehicle platform, Apollo.

Microsoft's Azure cloud-storage service will allow self-driving cars that run on the Apollo platform to store information, such as map and roadway updates, marking the latest evolution of a system that's had inputs from 50 automakers, suppliers, and other tech companies.

The expanded Baidu/Microsoft partnership is the latest effort from a technology company (or in this case, companies) to push into the budding self-driving car industry, where software, data, and technology are nearly as important as the car itself. 

Apollo's open-source nature makes it unique in the world of self-driving vehicles. Companies are free to use the platform in its entirety, or marry specific features to in-house technology. Apollo includes software that allows autonomous vehicles to locate themselves in their surroundings, plan routes, and control mechanical functions of the car.

Looking toward the future, Baidu is keen to become a leader in self-driving car software as a one-stop-shop for cutting-edge software, while Microsoft wants in on the promise of autonomous cars. However, the same can be said for dozens of Silicon Valley start-ups, established technology companies, and even traditional automakers.