Apple unveiled Lisa operating system on January 13, 1983. The Apple computer with Lisa costed $10000 at that time. The OS had a graphical user interface (GUI) and aimed at individual business customers. Apple could only sell only 10,000 units while it spent $150 million on R&D.
After failure, Apple discontinued Lisa in 1986. It died almost two decades back, but it is coming back next year. Thanks to the Computer History Museum, you will soon be able to use that historical operating system for free.The source code of Lisa’s operating system and applications have been recovered and it will be soon available on the museum.
As the source code will be available, you will be free to modify it and create something new based on it.
Even if Lisa couldn’t attract customers due to high cost, it brought some interesting features including HDD-based OS, File system, and protected memory. It was also one of the first computers to offer mouse. Lisa OS came with Lisa Office System that had seven apps including LisaWrite, LisaCalc, LisaDraw, LisaGraph, LisaProject, LisaList, and LisaTerminal.
Apple also launched Lisa 2 in 1984 that cost half of Lisa but it also failed to some magic. In 1984, Apple released Mac that was more affordable and improved version of Lisa. It became successful. So, Apple discontinued the Lisa project in 1986.
You can check this Lisa commercial
https://www.youtube.com/watch?v=W13kUWf5SAE
Source: Business Insider Singapore]