Unix wars

(The feasibility of this had been demonstrated a few years earlier by the US Army Ballistic Research Laboratory's System V environment for BSD Unix.)

[3] While this decision was applauded by customers and the trade press, certain other Unix licensees feared Sun would be unduly advantaged.

Technical issues soon took a back seat to vicious and public commercial competition between the two "open" versions of Unix, with X/Open holding the middle ground.

A 1990 study of various Unix versions' reliability found that in each version, between a quarter and a third of operating system utilities could be made to crash by fuzzing; the researchers attributed this, in part, to the "race for features, power, and performance" resulting from BSD–System V rivalry, which left developers little time to worry about reliability.

In March 1993, the major participants in UI and OSF formed the Common Open Software Environment (COSE) alliance, effectively marking the end of the most significant era of the Unix wars.

Mac OS X v10.5 is the first operating system with open source BSD code to be certified as fully Unix compliant.