In the past decades, Apple Inc. developed a few operating systems series for its computer products. There are four main ones: Apple DOS/ProDos/GSOS for Apple II computers, A/UX as a UNIX based OS for many Apple computer models, MacOS for Macintosh computers, and the MacOS X for the latest Apple computers.
In the table below, we listed the historic timeline for the evolution of the Apple computer operating systems.
| Date | OS Edition | Platform | Notes |
| 1971 | Apple I | For Apple I | The OS has no name. |
| 1977 | Apple DOS (DOS 3.x) | For Apple II | Last release was Apple DOS 3.3.2 in 1983 for Apple IIe. |
| Jan. 1983 | Lisa OS | For Apple Lisa Personal Computer | Discontinued in Aug. 1986. |
| Oct. 1983 | ProDOS 1.0 | For Apple II | 8 bit |
| Jan. 1986 | System 1.0 or “Classic” MAC OS 1.0 | For Macintosh Personal Computer | |
| Sept .1986 | ProDOS 8 1.2 | For Apple II | 8 bit; Last version is ProDOS 8 v1.9 released in Aug. 1990. |
| Sept. 1986 | ProDOS 16 | For Apple IIGS | 16 bit |
| March 1987 | System 2.0 or “Classic” MAC OS 2.0 | For Macintosh Personal Computer | |
| Oct. 1987 | System 5.0 or “Classic” MAC OS 5.0 | For Mac SE and Macintosh II. | |
| May 1987 | GS/OS v2.0 | For Apple IIGS | Based on the ProDOS 16 |
| Dec. 1987 | GS/OS v3.1 | For Apple IIGS | |
| April 1988 | System 6.0 or “Classic” MAC OS 6.0 | For Macintosh computers | |
| Feb. 1988 | AUX (A/UX) 1.0 | For Macintosh computers | Apple version of Unix based on Unix System V 2.2with MAC OS GUI. |
| Sept 1988 | GS/OS v4.0 | For Apple IIGS | |
| May 1989 | GS/OS System 5.0 or “Classic” MAC OS 5.0 | For Macintosh computers | |
| July 1989 | GS/OS v5.0 | For Apple IIGS | |
| 1990 | AUX 2.0 | For Macintosh computers | |
| May 1991 | System 7.0 “Classic” MAC OS 7.0 | For Macintosh computers | |
| March 1992 | GS/OS v6.0 | For Apple IIGS | The last release of GS/OS is v6.0.1 in July 1992; Apple IIGS was end of life in 1992. |
| 1992 | AUX 3.0 | For Macintosh II, Quadra and Centris | |
| 1995 | AUX 3.1.1 | For Macintosh II, Quadra and Centris | Last version of the AUX |
| Jan. 1997 | MacOS 7.6 | For Macintosh computers | The name MacOS was officially used starting from this version. |
| July 1997 | MacOS 8.0 | For Macintosh computers | |
| Oct .1999 | MacOS 9.0 | For Macintosh computers | |
| March 2001 | For Mac computers | For Mac computers | In 1996, Apple acquired the NeXT; OPENSTEP of NeXT, also BSD Unix and Mach, as well as the Mac OS 9.x were joint basis for Mac OS X. |
| Aug 2002 | For Mac computers | For Mac computers | |
| Oct 2003 | For Mac computers | For Mac computers | |
| April 2005 | For Mac computers | For Mac computers | . |
| Oct. 2007 | For Mac computers | For Mac computers |