A programming language in which you can model computer systems and a tool to help prove properties of those models. Available under GPL and runs on various platforms. Includes related download links.

Franz Allegro is a CL compiler available for Linux, Unix, and Windows. Free and commercial versions.

Lisp dialect by Paul Graham; readings in: design philosophy, lessons, why it isn't especially object-oriented, FAQ.

Newbie-friendly community, because all Arc users are new to some extent.

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]

ANSI Common Lisp implementation: descriptions, documents, FAQs, downloads, links, developers.

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]

World Wide Web server implemented in CL; goal: to rapidly prototype, smoothly evolve experimental, novel, or complex applications for the WWW. [Open Source]

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]

Corman Lisp and PowerLisp compilers with support for 68k and PPC Macs. [Shareware/Freeware for personal use]

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.

ANSI CL, has interpreter, Lisp to C compiler, can make standalone executables or libraries to call from C programs. [Open source, LGPL]

Embeddable Common Lisp, implementation to embed in C-based programs; FTP site.

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.

Level-0 description document with history, definitions.

CL interpreter. Home site: description, mail list, archives, news, CVS, downloads, links. [Open Source, GPL]

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.

Small dialect for low-end and embedded devices. Has compiler to bytecode and corresponding interpreter, coded in standard C, efficient, portable, can be compiled to very small executable or library. [Open Source, GPL]

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.

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.

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-scoped compiled language with Lisp syntax, (3) C language, can be freely mixed with Lush code in one program, even in one function.

Was Jargol. Proposal with wish/feature list.

Digitool's implementation of Logo for the Mac.

ISLisp interpreter, coded in C, ported to over 90 architectures, 16- to 64-bits. [commercial, free non-commercial use]

An open-sourced Common Lisp implementation for LinuxPPC.

A version of Berkeley Franz Lisp for 386-based NetBSD systems.

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.

Minimilist Lisp dialect and virtual machine. Reference, tutorial, FAQ. Downloads. [Open source, GPL]

An interpreter for a lexically scoped minimalistic Lisp of Lisp 1.5 type. It written in C++ and currently runs under Linux. [Open source]

Tiny Lisp in Python: brief description, download.

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]

Multi-threaded CL, supports symmetrical multiprocessor (SMP) Unix systems.

DOS CL implementation with CLOS. Download, full CL reference manual. From Sapiens Software Corp. [free copyrighted unsupported shareware]

Common Lisp development system. Includes command-line and IDE interpreters. Possibility of creating EXE-files. [Free non-commercial and education use]

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.

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 source, GPL]

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]

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.