Steel Bank Common Lisp is a development environment for Common Lisp, with excellent support for the ANSI standard: garbage collection, lexical closures, powerful macros, strong dynamic typing, incremental compilation, and the famous Common Lisp Object System (multimethods and all). It also includes many extensions, such as native threads, socket support, a statistical profiler, programmable streams, and more. These are all available through an integrated, interactive native compiler which feels like an interpreter. SBCL is unique in being a multiplatform native compiler which bootstraps itself completely from source, using a C compiler and any other ANSI Common Lisp implementation.
CMUCL is a free, high performance implementation of the Common Lisp programming language which runs on most major Unix platforms. It mainly conforms to the ANSI Common Lisp standard. CMUCL provides a sophisticated native code compiler; a powerful foreign function interface; an implementation of CLOS; the Common Lisp Object System; which includes multimethods and a metaobject protocol; a source-level debugger and code profiler; and an Emacs-like editor implemented in Common Lisp. CMUCL is maintained by a team of volunteers collaborating over the Internet, and is mostly in the public domain.
CodeWorker is a versatile parsing tool and a universal source code generator. It interprets a scripting language for producing reusable, tailor-made, evolving, and reliable IT systems with a high level of automation. The file formats to parse are described in an extended-BNF syntax. Template-based scripts drive the writing of patterns for generating code or text. The code generation knows how to preserve protected areas with hand-typed code and provides code expansion, source-to-source translation, and program transformation. It provides a native translation of CodeWorker's scripts in C++.
MDK (MIX Development Kit) provides tools for developing and executing, in a MIX virtual machine, MIXAL programs. The MIX is Donald Knuth's mythical computer, described in the first volume of The Art of Computer Programming, which is programmed using MIXAL, the MIX assembly language. MDK includes a MIXAL assembler (mixasm), a MIX virtual machine (mixvm) with a command line interface, a Guile-based virtual machine (mixguile), a GTK+ based GUI (gmixvm), and a mixvm-Emacs interface (mixvm.el). MDK utilities are extensible using Scheme.
Onyx is a powerful stack-based, multi-threaded, interpreted, general purpose programming language similar to PostScript and Forth. It can be embedded as an extension language into other applications, and was designed to have a small memory footprint. It is among the smallest embeddable interpreters available.
Q is a powerful and extensible functional programming language based on the term rewriting calculus. When programming with Q, you specify a system of equations which the interpreter uses as rewrite rules to reduce expressions to normal form. Q is useful for scientific programming and other advanced applications, and also as a sophisticated kind of desktop calculator. The distribution includes the Q programming tools, a standard library, add-on modules for interfacing to various third-party libraries, and an Emacs mode.
STklos is a free Scheme System conforming to R5RS. The implementation is based on an ad-hoc Virtual Machine. It can also be compiled as a library, so that one can easily embed it in an application. Its features include an efficient and powerful object system based on CLOS, a simple-to-use module system, implementation of the full tower of numbers defined in R5RS, and easy connection to the GTK+ toolkit. STklos is the successor of STk, a Scheme interpreter tightly connected to the Tk toolkit.