Clozure CL (formerly OpenMCL) 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)

Both 32- and 64-bit binaries are included with all ports.