| System | Year | Comments |
| System 0.97 | 1983 | A pre-release of the original System and Finder |
| System 1.0 | January 24, 1984 | Released with the 128K. |
| System 1.1 | Saturday, May 5, 1984 |
Improved disk copying speed on the 128K. |
| System 2.0 | April 1985 | Released with the 512K. Updated the finder, and released with 512Ke |
| System 3.0 | January 1986 | Released with the Plus. Added the Shutdown command. |
| System 3.1 | February 1986 | An update for the Plus. (Extremely buggy) |
| System 3.2 | June 1986 | The most stable and widely-used System |
| System 3.3 | January 1987 | Slightly updated |
| System 4.0 | March 1987 | First system software that couldn't be run on the 128K. |
| System 4.1 | April 1987 | Released with the SE and Mac II. INITs and CDEVs went loose in the System Folder. |
| System 4.2 | October 1987 | Was also called System Release 5.0. Ushered in the use of CDEVs and INITs. |
| System 5.1 | November 1987 |