Apple Lisa is famous for being the first computer with a graphical user interface (GUI), an approach to personal computer interfaces that Steve Jobs embraced after visiting Xerox's Palo Alto Research Center, or PARC, in 1979.
While most people remember the Apple Macintosh for its GUI, Hansen Hsu, a software curator at CHM who formerly worked on Mac OS X at Apple, notes in a blogpost there would be no mouse-driven Macintosh or Microsoft Windows without the Lisa.
"Apple's Macintosh line of computers today, known for bringing mouse-driven graphical user interfaces (GUIs) to the masses and transforming the way we use our computers, owes its existence to its immediate predecessor at Apple, the Lisa. Without the Lisa, there would have been no Macintosh—at least in the form we have it today—and perhaps there would have been no Microsoft Windows either," writes Hsu.
Priced at $9,995 in 1983, Apple Lisa was aimed at businesses and sported a Motorola 68000 microprocessor with a hard drive that turned out to be not enough for the Lisa's multitasking. Sales performed poorly against IBM's command-line interface PC for $1,565. Lisa followed the command-line Apple II, which was aimed at consumers.
The Apple Lisa included the operating system Lisa OS and several office applications, such as the word processor, LisaWrite, and the spreadsheet program, LisaCalc. Other programs included LisaTerminal, LisaGraph, LisaList, and LisaProject.
As noted by Hsu, Jobs was removed from the Lisa project in 1982 following a reorganization. He then discovered the Macintosh project that had been started by the late Jef Raskin. He took over the Mac project and brought across Lisa's mouse-driven GUI design, but at a more affordable price.
Apple started shipping the Apple Macintosh in January 1984 for $2,495 without a hard drive or multitasking. Apple announced the Lisa 2 series alongside the Macintosh for $3,495 and $5,495. The Apple Lisa source code is available from the CHM's website here.