Clozure CL supports the Mac OS X, Linux, FreeBSD, Solaris and Microsoft Windows platforms.
Clozure CL was used by ITA Software for the business logic of a new Airline Reservation System.
[4] Formerly known as OpenMCL, Clozure CL is an evolution of Macintosh Common Lisp.
CCL's compiler produces native instructions for Lisp expressions and files.
By default every expression entered at the REPL is compiled to native code.