MacWorks Plus was a complete implementation (port) of the Macintosh Plus 128K ROM on the Apple Lisa and Macintosh XL computer systems,  a contract developer named Chuck Lukaszewski, who was responsible for versions up through 1.1(h), which supported up to which graphical user interface-based operating system for Macintosh computers, and was shipped with various Macintosh computers until it was succeeded by System 7 in 1991?
System 6 System 6 (also referred to as System Software 6) is a graphical user interface-based operating system for Macintosh computers. It was released in 1988 by Apple Computer and was part of the classic Mac OS line of operating systems. System 6 was shipped with various Macintosh computers until it was succeeded by System 7 in 1991. The boxed version of System 6 cost $49 when introduced. System 6 is classed as a monolithic operating system. It featured an improved MultiFinder, which allowed for co-operative multitasking.
Jerry Manock Jerrold Clifford Manock (born February 21, 1944) is an American industrial designer. He worked for Apple Computer from 1977 to 1984, contributing to housing designs for the Apple II, Apple III, and earlier compact Apple Macintosh computers. Manock is widely regarded as the "father" of the Apple Industrial Design Group. Since 1976 he is the president and principal designer of Manock Comprehensive Design, Inc., with offices in Palo Alto, California, and Burlington, Vermont.