Starting from remarkably humble beginnings over three decades ago, open source software (OSS) is the story of a better mousetrap that wins over the world. Originally, the intent of open source projects was to create software that system administrators and developers could use without having to pay licensing fees — but OSS has become much, much more. Now, 30 years after the first release of arguably the best-known OSS technology, the Linux operating system, there is a rich ecosystem of OSS technologies that provide solutions for just about any layer of software that a given organization might want or need — for virtually any platform or architecture — ranging from IBM Z at the high end to ARM-based edge devices. This IDC Technology Spotlight takes a deeper look at the value proposition associated with using commercially supported OSS in mission-critical environments, such as IBM Z.