In 1984, Coral Software began the development of a Common Lisp for the Macintosh, called Coral Common Lisp (CCL). Three years later, CCL 1.0 was released. It ran on a 1 MB Macintosh Plus.

Subsequently, Coral entered into a marketing relationship with Franz, under which CCL was renamed to Macintosh Allegro Common Lisp (MACL). That didn't last long, and in late 1988, Coral was acquired by Apple, who released the Lisp under the name Macintosh Common Lisp (MCL).

In 1994, in the midst of switching from the 68K to the PowerPC CPU for its Macintosh line, Apple transferred MCL to Digitool. Digitool completed the PowerPC port and released a PowerPC version of MCL around 1995.

Erann Gat (now known as Ron Garret) of JPL wanted to develop a small-footprint Lisp for use on PowerPC-based robots and flight systems. A source license for MCL was acquired from Digitool, and in 1998, Gary Byers ported a version of the MCL compiler and runtime to VxWorks and LinuxPPC. In 2001, Digitool agreed to open source the work that had been done at JPL, and OpenMCL was born.

In 2007, Alice Hartley of Digitool announced that the code for the original MCL would be released under an open source license. Largely in order to avoid confusion with this newly open sourced version of MCL, OpenMCL was renamed to Clozure CL. As a bonus, this makes the name of the primary implementation package and the default installation directory name ("ccl") meaningful again.

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