But today's breakthroughs would be nowhere and would not have been possible without what came before them - a fact we sometimes forget. Mainframes led to personal computers, which gave way to laptops, then tablets and smartphones, and now the Internet of Things. Today much of the interoperability we enjoy between our devices and systems - whether at home, the office or across the globe - owes itself to efforts in the 1980s and 1990s to make an interoperable operating system (OS) that could be used across diverse computing environments - the UNIX operating system.
As part of the standardization efforts undertaken by IEEE, it developed a small set of application programming interfaces (APIs). This effort was known as POSIX, or Portable Operation System Interface. Published in 1988, the POSIX.1 standard was the first attempt outside the work at AT&T and BSD (the UNIX derivative developed at the University of California at Berkeley) to create common APIs for UNIX systems. In parallel, X/Open (an industry consortium consisting at that time of over twenty UNIX suppliers) began developing a set of standards aligned with POSIX that consisted of a superset of the POSIX APIs. The X/Open standard was known as the X/Open Portability Guide and had an emphasis on usability. ISO also got involved in the efforts, by taking the POSIX standard and internationalizing it.
A short look at the history of UNIX standardisation and POSIX.