### 2.1 Supported Platforms ¶

SLIME supports a wide range of operating systems and Lisp implementations. SLIME runs on Unix systems, Mac OSX, and Microsoft Windows. GNU Emacs versions 24 and 23.4 are supported. XEmacs is not supported anymore.

The supported Lisp implementations, roughly ordered from the best-supported, are:

- CMU Common Lisp (CMUCL), 19d or newer
- Steel Bank Common Lisp (SBCL), 1.0 or newer
- Clozure Common Lisp (CCL), version 1.3 or newer
- LispWorks, version 4.3 or newer
- Allegro Common Lisp (ACL), version 6 or newer
- CLISP, version 2.35 or newer
- Armed Bear Common Lisp (ABCL)
- Corman Common Lisp, version 2.51 or newer with the patches from http://www.grumblesmurf.org/lisp/corman-patches)
- Scieneer Common Lisp (SCL), version 1.2.7 or newer
- Embedded Common Lisp (ECL)

Most features work uniformly across implementations, but some are prone to variation. These include the precision of placing compiler-note annotations, XREF support, and fancy debugger commands (like “restart frame”).