Apple’s flagship Lisa has become “open source” thanks to the Computer History Museum

as part of Apple Lisa 40th Birthday Celebrations, Computer History Museum Source code released for Lisa OS version 3.1 under the Apple Academic License Agreement. With Apple’s blessing, Pascal source code is available for Download From the Clearing-House website after filling out a form.

Lisa Office System 3.1.1 Dating back to April 1984, during the early Mac era, today was the equivalent of Lisa for operating systems like macOS and Windows.

The entire source package is about 26MB in weight and consists of over 1,300 commented source files, nicely divided into subfolders that reference the main Lisa OS code, several included applications, and the Lisa Toolkit development system.

First released on January 19, 1983, the Apple Lisa remains an influential and important device in Apple’s history, pioneering the mouse-based graphical user interface (GUI) that made its way to the Macintosh a year later. Despite its innovations, the Lisa’s high price ($9,995 retail, or about $30,300 today) and lack of app support stopped it as a platform. A year after its release, the Macintosh with similar capabilities has drastically reduced its price. Apple launched a major revision of the Lisa hardware in 1984, then discontinued the platform in 1985.

The Lisa wasn’t the first commercial computer to ship with a graphical user interface, as some have claimed in the past—that honor belongs to Xerox Star—but the Lisa OS Known Important conventions that we still use in today’s window operating systems, such as drag-and-drop icons, animated windows, trash, menu bar, drop-down menus, Copy and paste shortcutsControl panels, nested windows, and even one touch Automatic shutdown of the system.

With the release of the LisaOS source code, researchers and educators will now be able to study how Apple developers implemented those historically important features four decades ago. Apple’s academic license permits use and compilation of the source code “for non-commercial academic research, educational instruction, and personal study purposes only.”

It used to be the Computer History Museum release sneered From the code in 2018, but after spending some time reviewing, they decided to delay its release until the computer’s 40th birthday—the perfect gift to honor the legacy of this important machine.