Open source software is developed to be a community good rather than the property or operation of a single corporation or individual. It is produced collaboratively, shared freely, published openly, and developed in a transparent manner. There isn’t a single point of contention in the development of an open source project, and neither is there a maker, owner, or seller of the program.
The software that builds the Bitcoin network when it is run on computers connected to the internet is not produced by a single firm, just as the Bitcoin network is not powered by a single company. For people unfamiliar with software development, the decentralization of technology production has a number of significant advantages that can be challenging to understand.