Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Mac OS X Server 1.0, released on March 16, 1999, is the first operating system released into the retail market by Apple Computer based on their acquisition of NeXT. It followed the Rhapsody series of developer releases of what was to be known as Mac OS X. Although OS X Server 1.0 had a variation of the Platinum "look and feel" from Mac OS 8, it is based on the OPENSTEP operating system instead of the classic Mac OS, giving users a preview of the future operating system Mac OS X. It was replaced by a version based on Mac OS X v10.0 in 2001.