Mesosphere, a cloud infrastructure startup popular with developers, will start offering its flagship product for free, according to people briefed about the move. It marks a major shift in the company's business model and offers more proof of the challenges of building a business around open-source software.

Mesosphere will give away the source code for its “Data Center Operating System,” which helps developers write apps that run in data centers and can handle traffic of millions of users. The move reflects mounting pressure from Google, whose own freely available cloud infrastructure software, called Kubernetes, does some of the things Mesosphere had been trying to charge for.