In truth, there’d be no DevOps without open source.
There is a whole chain of events, dare I say a perfect storm of technologies and philosophies rising to prominence that rendered inevitable the rise of DevOps or something like it. Open source projects rose up that gave us free operating systems that made the modern dynamic web an economic feasibility. Linux and GNU weren’t the least of these things. Certainly middleware, relational (and non-relational) databases, and myriad programming languages rose up through the open source community that provided the technical scaffolding needed for DevOps success.