ACL2
   Applicative Common Lisp, multipurpose system. Most common uses: language for programming, specification, modeling; a formal mathematical logic, semi-automatic theorem prover. [Open Source, GPL]
   http://www.cs.utexas.edu/users/moore/acl2/

Allegro CL
   Franz Allegro is a CL compiler available for Linux, Unix, and Windows. Free and commercial versions.
   http://www.franz.com/products/

Arc
   New Lisp dialect, by Paul Graham. Software unreleased, but readings in: design philosophy, lessons, why it isn't especially object-oriented, FAQ.
   http://www.paulgraham.com/arc.html

Armed Bear Common Lisp
   ANSI CL, runs on Java Virtual Machine, JVM. Has runtime system, compiler turns Lisp source to JVM bytecode, interactive REPL to develop programs. [Open Source, GPL]
   http://armedbear.org/abcl.html

CLISP
   ANSI Common Lisp implementation: descriptions, documents, FAQs, downloads, links, developers.
   http://clisp.cons.org/

CMU Common Lisp: CMUCL
   CL implementation, runs on most major Unix platforms, mainly conforms to ANSI CL standard; fast compiler outputs native code, of near C speed; powerful module system, data structures. [Freeware]
   http://www.cons.org/cmucl/

Common Lisp Hypermedia Server: CL-HTTP
   World Wide Web server implemented in CL; goal: to rapidly prototype, smoothly evolve experimental, novel, or complex applications for the WWW. [Open Source]
   http://www.cl-http.org:8001/cl-http/

Common Lisp to C Compiler: CLiCC
   Not a CL system, compiles Lisp programs into working C programs; is coded in Lisp; supports strict, very large subset of CL + CLOS. Descriptions, documents, downloads. [Open Source, GPL]
   http://www.informatik.uni-kiel.de/~wg/clicc.html

Corman Technologies
   Corman Lisp and PowerLisp compilers with support for 68k and PPC Macs. [Shareware/Freeware for personal use]
   http://www.cormanlisp.com/

Digitool, Inc.
   Makes Macintosh Common Lisp, MCL: for 68k, PowerPC; compiles to native code, supports threads, integrates well into Mac OS, fun; Common Lisp Interface Manager, CLIM: platform independent user interface system, to target other Lisp platforms.
   http://www.digitool.com/

DotLisp
   Interactive Lisp dialect for CLR (.Net) scripting, development. Deep CLR integration, sharing type system, GC, other runtime services, transparent access to .Net w/o a FFI or wrappers. Open source, BSD.
   http://dotlisp.sourceforge.net/

ECL: Embeddable Common Lisp
   ANSI CL, has interpreter, Lisp to C compiler, can make standalone executables or libraries to call from C programs. [Open source, LGPL]
   http://ecls.sourceforge.net/

ECoLisp: ECL
   Embeddable Common Lisp, implementation to embed in C-based programs; FTP site.
   ftp://ftp.di.unipi.it/pub/lang/lisp/

EuLisp
   Dialect of scope similar to Common Lisp, object-oriented, but organized differently, with claimed cleaner design, by a group of European industrial and academic Lisp users and implementors. Description, FTP server, contacts, links.
   http://www.aiai.ed.ac.uk/~jeff/lisp/eulisp.html

EuLisp Programming Language
   Level-0 description document with history, definitions.
   http://people.bath.ac.uk/masjap/EuLisp/

GNU Common Lisp: GCL
   CL interpreter. Home site: description, mail list, archives, news, CVS, downloads, links. [Open Source, GPL]
   http://www.gnu.org/software/gcl/

GOO
   Generic Object Orientator, replaces Protojunior: OO, type-based prefix-syntax language; like a simpler, more dynamic, Lispy Dylan and OO Scheme; simple, efficient, extensible. Description, manual, rationale, downloads.
   http://people.csail.mit.edu/jrb/goo/

L Sharp .NET
   Lisp-like scripting language for .NET; uses Lisp dialect similar to Arc but tightly integrates with .NET Framework which provides a rich set of libraries. Open source GPL.
   http://www.lsharp.org/

LispWorks Ltd.
   Was Xanalys. Makes LispWorks ORB, Liquid Common Lisp, KnowledgeWorks; integrated cross-platform development tool, full native ANSI Common Lisp for Linux, Mac OS X, Unix, Windows; related products, services. Free and commercial versions.
   http://www.lispworks.com/

Lush: Lisp Universal SHell
   Object-oriented language for researchers, experimenters, engineers, for large-scale numerics and graphics. Merges 3 languages: (1) weakly-typed, garbage-collected, dynamically scoped, interpreted language with Lisp syntax, (2) strongly-typed, lexically-sc
   http://lush.sourceforge.net/

Manifesto on JAR's Next Language
   Was Jargol. Proposal with wish/feature list.
   http://mumble.net/~jar/articles/language-manifesto.html

OpenMCL
   An open-sourced Common Lisp implementation for LinuxPPC.
   http://openmcl.clozure.com/

Opus
   A version of Berkeley Franz Lisp for 386-based NetBSD systems.
   http://www.aiai.ed.ac.uk/~jeff/franz-for-386.html

PLisp
   Language gets overall syntax from Common Lisp and operators and datatypes from PostScript (PS). Compiler translates PLisp to PS, which can then run on any PS engine. Wiki page with description, links, code samples.
   http://www.cliki.net/PLisp

Pico Lisp
   Minimilist Lisp dialect and virtual machine. Reference, tutorial, FAQ. Downloads. [Open source, GPL]
   http://software-lab.de/ref.html

ProLisp
   An interpreter for a lexically scoped minimalistic Lisp of Lisp 1.5 type. It written in C++ and currently runs under Linux. [Open source]
   http://www.aviduratas.de/lisp/prolisp.html

PyLisp
   Tiny Lisp in Python: brief description, download.
   http://www.biostat.wisc.edu/~annis/creations/PyLisp/

SBCL: Steel Bank Common Lisp
   Compiler and runtime system for ANSI CL. Has interactive environment including an integrated native compiler, debugger, many extensions; runs on many platforms. [Open Source, GPL]
   http://sbcl.sourceforge.net/

Scieneer Common Lisp: SCL
   Multi-threaded CL, supports symmetrical multiprocessor (SMP) Unix systems.
   http://www.scieneer.com/scl/

Star Sapphire Common Lisp
   DOS CL implementation with CLOS. Download, full CL reference manual. From Sapiens Software Corp. [free copyrighted unsupported shareware]
   http://www.webweasel.com/lisp/

Ufasoft Lisp
   Common Lisp development system. Includes command-line and IDE interpreters. Possibility of creating EXE-files. [Free non-commercial and education use]
   http://www.ufasoft.com/lisp/

Wade's Common Lisp: WCL
   Implements CL for Linux on x86 hardware, has large CL subset as a shared library that can link with Lisp and C code to make efficient, small programs; suitable for embedding in other programs.
   http://wcl.kontiki.com/

librep
   Shared library implementing Lisp dialect that is lightweight, fairly fast, highly extensible. Has interpreter, byte-code compiler, virtual machine. Programs may use interpreter as an extension language, or it may be used for standalone scripts. [Open sour
   http://librep.sourceforge.net/

newLISP
   General purpose scripting Lisp dialect for Cygwin, FreeBSD, Linux, Mac OS X, Solaris, Win32; like Scheme but with dynamic scoping; GUI version has IDE with editors and source level debugger, Tcl/Tk frontend. [Open Source, GPL]
   http://www.newlisp.org/

pLISP
   Experimental implementation of parallel functional programming. Built as a hybrid architecture, uses simple Lisp interpreter to drive the compiler, and wraps calls to the Graph-reduction VM.
   http://www.thinkartlab.com/pkl/tm/plisp/