In 1979, Apple had seen a need to complete the Apple II, series. After a visit to the Xerox PARC (Palo Alto Research Center) where he saw lots of new technologies (Ethernet network, GUI, OOP & Laser Printers), Steve Jobs (then chairman of Apple) decided to launch a graphical computer. After lots of work (and two rejected prototypes along the way), the Lisa was revealed in January 1983.

Lisa was the original code-name. Supposedly, the Lisa was named after Steve Jobs' eldest daughter, Lisa Nicole. The Lisa project cost over $50 million and was the result of more than 200 person-years of research and development. It was supposed to be the Next Big Thing. It was not however the first personal computer to use a Graphical User Interface (GUI). Several Xerox systems developed in Palo Alto, utilized the STAR operating system. STAR contained a very innovative icon-based interface as well as a built-in word processor and calculator.

Contrary to the "legend", Lisa was not the ancestor of the Macintosh. Lisa and Macintosh were two distinct projects. The original Lisa couldn't use Macintosh programs and Macintosh couldn't run Lisa software. The LISA OS (Office System) was a true preemptive multitasking operating system.

Because of its very high price ($9,999.99 USD in 1983!) and because of competition with the Macintosh, the Lisa was one of Apple's biggest flops (alongside the Apple 3 and the Newton!). A new version of Lisa was presented in January 1984, the Lisa 2. It had virtually same features but used a 3.5" 800 KB floppy drive instead of the old 5.25" "Twiggy" floppy drives. Three versions of the Lisa 2 were successively released:
* Lisa 2 basic version which had rather less memory (512 KB instead of 1 MB) and storage capability than the first Lisa
* Lisa 2/5, the nearest to the Lisa 1 at approx. half the original price, was sold with a 5 MB 'Profile' hard disk unit
* Lisa 2/10, which offered up to 10 MB of storage on an internal hard-disk.
All Lisa's were expandable systems thanks to three slots in the back, mainly used for RAM expansion cards. Up to 7 drives hooked up at once on the same interface.

In 1985, the Lisa lost its name and was renamed "Macintosh XL" (the Lisa 2 could become a Mac XL through the replacement of a ROM chip on the inside of the machine), its ROM and its display was modified to use the Macintosh Operating System and was presented as a development system for the Macintosh (Don't forget - in 1985 there was no hard disk available for the Macintosh). The Macintosh XL was sold until 1986 but became obsolete when the new "True" Macintoshes were launched (Macintosh II and Mac SE in 1987).

After the Mac Plus came out, all owners of Lisa's and previous Macintoshes were offered the option to exchange their old computers for the new Plus (for a fee of course).