30 Years Apple Macintosh - we've been able to use a lot of Lisp on the Mac over the years: especially Macintosh Common Lisp, Symbolics MacIvory 3, LispWorks and Clozure CL. Thanks to Apple, Clozure Associates, Symbolics, LispWorks, and many other implementers and vendors.
The Apple Macintosh and Common Lisp were revealed in the same year: 1984. The first book on Common Lisp was published by Guy L. Steele Jr. as Common Lisp the Language. Soon Coral Software began to work on an implementation. In 1987 Macintosh Common Lisp was released. At the end of 1988 it was bought by Apple and used in many projects of the Advanced Technology Group. 1994 Macintosh Common was taken over to Digitool and it was then available on the PowerPC-based Mac. In 2008 a version was open-sourced as OpenMCL and ported to different platforms. OpenMCL was later renamed to Clozure CL and is now supported by Clozure Associates. Clozure CL was used by ITA Software in two large projects. ITA Software then was bought by Google.
In 1988 Symbolics Inc. released the Macivory Lisp Machine as a set of NuBus cards for the Apple Macintosh II. An adapter for the classic Symbolics keyboard completed the offering. The last model was the MacIvory 3 from 1991. It was just one Nubus board with a daughter board for added memory.
Also in 1988 Texas Instruments released the TI MicroExplorer, their Nubus card sized Lisp Machine for the Apple Macintosh II.
Some other forgotten Mac OS Common Lisp implementation: Exper Common Lisp and Procycon Common Lisp.
With the advent of the Unix-based Mac OS X several old implementations disappeared, but many new Common Lisp implementations were ported to the Mac: especially SBCL, Allegro CL and LispWorks. LispWorks 4.3 was released in 2003. The latter also got its development environment ported using a backend to Apple's Cocoa user interface library. Thus the 64bit LispWorks with the native user interface is the best ever Lisp implementation.
Mac OS X applications have been developed using LispWorks. Though Clozure CL also has direct support for Cocoa, less GUI applications have been developed. Would be great if that could change.