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.
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.
Jess is a fast, light rule engine and scripting environment written entirely in Java. You can build Java software that has the capacity to "reason" using knowledge you supply in the form of declarative rules. It is supplied as a programmer's library, making it ideal for embedding in larger applications. Jess includes development tools built on the Eclipse platform. It is free for academic use and can be licensed for commercial use.
MetaRuby contains miscellaneous libraries (useful now) for a future Ruby-in-Ruby interpreter including Array/Hash/String as abstract ("Hollow") classes, an undo queue, a statistical time-profiler, an event loop, a modular marshaller ("ToSource"), a specification for a modular+reflexive+homoiconic remote call system ("LGRAM"), a declarative type system, a schema for expressing Ruby source code as proper (non-special) Ruby objects, etc.
Gamma is a dynamically-typed, object-oriented, interpreted programming language that has been designed and optimized to reduce the time required for building applications. It supports the QNX/Photon and Linux/GTK GUI environments, and has a built-in library of over 300 functions. It cuts development times and offers run-time debugging by wedding a C-like syntax to a Lisp interpreter that has been optimized specifically for performance and memory usage.
Lush is a Lisp dialect with extensions for object-oriented and array-oriented programming. It is intended as a programming environment for prototyping numerically intensive applications. Unlike alternatives like Python or SciLab, Lush is designed for easy integration of existing C/C++/Fortran codes.
RScheme is an object-oriented, extended Scheme implementation with a compiler that targets C or (RScheme's own) bytecodes. It has features expected from a modern language: an object system, reflection, modules, namespaces, safe macros, threads, a system call interface (including sockets), separate compilation, and persistence, as well as the formal basis and power of the Scheme programming language. RScheme also features a powerful, elegant foreign code interface.
ACDK is a development framework with a similar target of Microsoft's .NET or Sun's ONE platform, but it uses C++ as a core implementation language. It implements the standard library packages, including acdk::lang, acdk::lang::reflect, acdk::util, acdk::io, acdk::text (including regexpr), acdk::net, acdk::sql, acdk::xml, and more. Flexible allocator/garbage collection, threading, and Unicode are implemented in the core of ACDK. Extensions make C++ objects available for reflection, serialization, aspect-oriented class attributes, and [D]ynamic [M] ethod [I]nvocation. This DMI acts as an universal object oriented call interface to connect C++ with scripting languages (Java, Perl, Tcl, Python, Lisp, Visual Basic, and VBScript) and standard component technologies (CORBA and COM).