The Software System 5 , wrongly called System 5 , is a Operating system Ordinateur Macintosh, published by Apple in 1987.

It was the first of the name to carry a unified number of version (hitherto, the Mac systems were indicated by a version of the Finder and a version of the System itself). In the software System 5, the " system" itself posted version 4.2, and Finder version 6.0.

System 5 introduced the MultiFinder, which made it possible the applications to function in background, in opposition to Finder, in which, among all the opened applications, only that which was in the foreground could exécuter.
Another important contribution was Color QuickDraw, supported by the Macintosh II. This evolution significantly changed the extent and the design of fundamental architecture graphics.

History of the versions

• October 1987: Software System 5.0 (System 4.2, Finder 6.0, MultiFinder 1.0)

• Software System 5.1 (System 4.3, Finder 6.0, MultiFinder 1.0)