Early versions, based on BSD UNIX, were called SunOS. The shift to a System V code base in SunOS 5 was marked by changing the name to Solaris 2 (and earlier versions were retroactively named Solaris 1.x). After version 2.6, Sun began to drop the "2." from the name; the most recent versions (as of early 2002) are Solaris 7 and the 64-bit Solaris 8. The Solaris 9 Operating Environment was released 22 May 2002.
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