Version 92 (modified by rme, 8 years ago) (diff)


About Clozure CL

Clozure CL is an open source Common Lisp implementation that runs on the following platforms:

  • Mac OS X 10.4 and later (PowerPC and x86)
  • Linux (PowerPC and x86)
  • FreeBSD 6.x and later (x86)
  • Solaris (x86)
  • Microsoft Windows (x86)

Some distinguishing features of the implementation include:

  • fast compilation speed
  • native OS threads
  • precise, generational, compacting garbage collector
  • convenient foreign-function interface

Clozure CL used to be called OpenMCL. It is also sometimes called CCL. You will see the three names being used interchangeably.

Getting Clozure CL

The most recent released version of Clozure CL is version 1.3.

The preferred way to get Clozure CL is via Subversion. For example, to get Clozure CL 1.3 for Darwin/x86, you'd type (where the $ is the shell prompt):

$ svn co

You can get versions for other platforms by changing the darwinx86 to one of linuxx86, freebsdx86, solarisx86, windows, darwinppc, or linuxppc.

Please see  Obtaining, Installing, and Running Clozure CL for details on completing the installation.

If you don't have Subversion installed, you can download an earlier version from the table below. All these archives are available via anonymous ftp at

Darwinsvn only 1.2 ( dmg) 1.2 ( dmg)
FreeBSDsvn only 1.2
Linuxsvn only 1.2 1.2
Solarissvn onlysvn only
Windowssvn onlysvn only

After installing CCL, read about getting updates and bug fixes.


The Clozure CL manual is available on the web at or As of Clozure CL 1.2, the DocBook sources for the manual are included with the distribution.

We have started to collect a list of FrequentlyAskedQuestions.


Mailing Lists

There are two CCL-related mailing lists hosted at Click on a list's link to subscribe or to view archived messages.


Everyone interested in Clozure CL is welcome to participate in #ccl on The  channel logs are available. We also keep  logs for #lisp and  logs for #scheme.

Paid Support

 Clozure Associates provides commercial support and consulting services for Clozure CL as well as other Common Lisp implementations. These services can range from helping you debug your software to adding extensions to CCL, to providing several full time Lisp programmers to help you build your application. Please contact us at business@… for more information.

Starting Points

CCL Basics

Contributing to CCL

In-Depth CCL

Orient Yourself to Clozure CL Culture