Machines from Xerox running Interlisp-D. The computers had acronyms starting with D. Xerox later also integrated Common Lisp into Interlisp-D.

The hardware was not powerful - for example they had very little RAM.

But an emulator was developed for SPARC/UNIX and X86/Linux. Called Medley.

Alto descendants from PARC, ranging in size (not year built) from the Dandelion (AKA Xerox Star) Dolphin and Dorado (an ECL logic screamer). You could boot them into standalone environments like Smalltalk, Interlisp-D, and Cedar/Mesa). By “standalone” I mean you loaded specific microcode into the machine and then booted an environment in which everything: OS, GUI, file system etc was written in that environment.

When I worked at PARC I mostly used Interlisp, but I did use all those environments.

Late-70s early 80s Xerox "D machines": Xerox Dorado, Dolphin, Dandeline, ...