Actually Smalltalk was earlier inspired by Lisp. Lisp already had persistent heap images in 1960 in the first implementation.
A development environment with persistent heap images was already provided by BBN Lisp in the late 60s. The in-image structure editor for BBN Lisp came in 1968. A "make" like feature came in 1971.
Xerox then took BBN Lisp and developed it as Xerox Interlisp from 1972 onwards. Masterscope then was a source code management system in 1973. 1974 it ran on the Alto with a microcoded implementation. 1976 Interlisp got a window system and a virtual machine specification.
Xerox Interlisp-D then ran on the same hardware (the D-machines) as Smalltalk -> it was another operating system option. It basically appeared at same time as Smalltalk 80. Smalltalk and Interlisp were developed by different teams (with some overlap), in the same company and also for the same hardware.
The MIT Lisp Machines were inspired by the Xerox systems, but were different hardware with a slightly different target audience and different approaches in software development. Xerox was a commercial company with PARC as a research lab. The MIT AI lab was a well funded research lab at an university (MIT). Their more powerful systems were mainly developed for their AI researchers.
A development environment with persistent heap images was already provided by BBN Lisp in the late 60s. The in-image structure editor for BBN Lisp came in 1968. A "make" like feature came in 1971.
Xerox then took BBN Lisp and developed it as Xerox Interlisp from 1972 onwards. Masterscope then was a source code management system in 1973. 1974 it ran on the Alto with a microcoded implementation. 1976 Interlisp got a window system and a virtual machine specification.
Xerox Interlisp-D then ran on the same hardware (the D-machines) as Smalltalk -> it was another operating system option. It basically appeared at same time as Smalltalk 80. Smalltalk and Interlisp were developed by different teams (with some overlap), in the same company and also for the same hardware.
See the history&timeline of Interlisp: https://interlisp.org/doc/info/history.html
Interlisp has been open sourced: https://interlisp.org/
The MIT Lisp Machines were inspired by the Xerox systems, but were different hardware with a slightly different target audience and different approaches in software development. Xerox was a commercial company with PARC as a research lab. The MIT AI lab was a well funded research lab at an university (MIT). Their more powerful systems were mainly developed for their AI researchers.