Apple Lisa
From Computer History Wiki
This is the famous Lisa, the precursor to the Macintosh. The Lisa was trying for the 3M's of the time... 1 million bytes of ram (1Mb), 1Mb of storage, and a 1000x1000 display... While falling short in the display area the Lisa came close. The first generation Lisa's were also noted for having a 'twiggy' drive, a modified 5 1/4" drive. Lisa's also had a 5Mb profile hard disk.
Not surprisingly, the Lisa had a BIG price tag, I remember it being $10,000 USD. It's not surprising to say it was not a commercial success. Once it became clear the Lisa was not going to make it, they were rebranded as Macintosh XL's.
Operating Systems
While the Lisa's shipped with "Lisa Office System", they did have a few different OS's.
Emulators
There are a few good Lisa emulators...