Over time improvements to Unix were developed by others under license from AT&T. They used the AT&T source code but generally did not use its Unix trademark. Important examples from the 1980s include [[BSD]], [[SunOS]] and [[Xenix]]. | Over time improvements to Unix were developed by others under license from AT&T. They used the AT&T source code but generally did not use its Unix trademark. Important examples from the 1980s include [[BSD]], [[SunOS]] and [[Xenix]]. |