AIX, IBM's version of Unix, celebrated its 20th birthday this month.
The operating system was first introduced in January 1986, a time when there were numerous variations of the operating system initially developed by AT&T but widely licensed to others. In the two decades since, Unix has penetrated mainstream businesses, and the major Unix options have consolidated to AIX, Sun Microssytems' Solaris and Hewlett-Packard's HP-UX.
IBM's Unix version is under fire, however, because of the SCO Group's lawsuit against Big Blue. SCO, which inherited the AT&T Unix contract with IBM, argues IBM moved code into open-source Linux from AIX and Dynix--another Unix version IBM acquired in 1999. As a result, SCO tried to revoke IBM's Unix licenses in 2003.
IBM says SCO's claims are bogus and that its Unix rights are perpetual. In the years since SCO's suit began, IBM has increased its Unix server market share and, by IDC's measurement, reached No. 1 in revenue in the second quarter of 2005.
Big Blue also is a major backer of Linux, and Sun delights in accusing Big Blue of being conflicted in its priorities. Indeed, one top IBM server executive called Linux the "logical successor" to Unix. However, IBM persists in developing AIX. In December, for example, it announced the opening of its AIX Collaboration Center in Austin, Texas, and said it would spend $200 million there to test software on AIX and encourage innovation atop the operating system.