Virtual

Virtual is a control panel utility developed Connectix to enable virtual memory in classic Mac OS, years before Apple Computer had implemented it in System 7.

History
Virtual was released for System 6 by Connectix in 1989 as their original flagship product. It was updated for System 7 and had the advantage of requiring less disk space than Apple's own implementation of virtual memory. Virtual was superseded by RAM Doubler, which added the capability of for further improved performance by reducing reliance on disk swapping.