Time-sharing system evolution

The following tables provide links to major early time-sharing operating systems, showing their subsequent evolution.
* To avoid listing every multi-user system ever built (including virtually every system in use today), the goal here is to list:
** "Influential systems"
** Built "between 1960-1990"
* For clarity, the direct successors of these systems are also included, as well as several important interactive systems that, although not multi-user, had an impact on user interface design.
* Family relationships have been shown where practical, to help structure the tables. However, the intent is to provide a simple, compact set of links to all these systems – not to illustrate every relationship. See each system's main article for further details; all had many direct and indirect influences.

"About the term" time-sharing: : In the 1960s, time-sharing was a new concept, a departure from the batch processing approach previously used with computers. The idea of an individual user being able to initiate a computer job at a particular time, and to see results immediately, was regarded as strange – and probably wasteful. Computers were very expensive, and individual users had to conform to the computer's schedule, not vice versa. Time-sharing systems were thus a major change and, for a generation, represented a distinct category of operating system. Famous political battles were waged at IBM and elsewhere over this issue. Today, of course, virtually all operating systems are time-sharing systems.

Time-sharing system families

See details and additional systems in the table below. Relationships shown here are for the purpose of grouping entries and do not reflect all influences (e.g. OS/2 was more influenced by VAX/VMS than by MS-DOS, but its legacy is as an x86 platform).

ystem descriptions and relationships

References

ee also

*History of CP/CMS for many period details and sources.
*Timeline of operating systems