Clozure CL is an implementation of Common Lisp, an object-oriented dynamic programming language. It includes a fast compiler, support for native threads, a sophisticated garbage collector, and a convenient interface for calling C and Objective-C code.

What’s New

Version 1.11.7

Now bundles ASDF 3.3.3.

Fix a crash on startup and a crash involving the search files dialog.

Ratings and Reviews

3.8 out of 5
22 Ratings

22 Ratings

pythonian ,

still doesnt work on Catalina out of box

says Error: The value #<A Foreign Pointer #x71A8B0> is not of the expected type OBJC:OBJC-OBJECT

got the source from clozure site,installed the ccl64 script in /usr/local/bin and it started working.

BillInWebster ,

Outstanding CL, true Mac UI, no extra junk

I teach AI and Lisp at the university level and was looking for a true Common Lisp implementation for the Mac that will let you develop serious projects, but not have all the Rube Goldberg extras of overly-engineered (and either expensive or limited) alternatives. CCL is the best — and I’ve used Lisp, many development environments, for a lot longer than my students have been alive. Nice, clean interface, easy for a beginnner to learn and manage, but with the full power of Lisp under it. Only complaint is that there’s no way I can see to pay for this software. I woud do that happily, and ask my students to do so as well.

Green Screen Crusader ,

Works great... if you're still on High Sierra

My High Sierra laptop has a swollen battery, so I've been forced to upgrade to a new Catalina laptop. I already knew what to expect from experience trying to get CCL to work on Mojave.

CCL is just broken on MacOS versions later than High Sierra, and that's just sad, because it was the only open-source Lisp implementation that supported GUI programming on the Mac. Perhaps it's finally time to buy a proprietary Lisp. :(


Clozure Associates, LLC
32 MB

OS X 10.6.6 or later, 64-bit processor



Age Rating


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