HGL is a compiler/interpreter suite for developing images. It features its own simple but powerful language, Lua integration, output in various formats as well as runtime input handled by plugins, and easy integration into various environments like Web servers or graphical applications. The input is taken from a source file, which has to be compiled for quick and frequent access by the interpreter. An interpreter then runs the compiled files, takes input from custom plugins (if neccessary), and outputs its result via custom plugins.
Gforth is a fast and portable implementation of the ANS Forth language. It works nicely with the Emacs editor, offers some nice features such as input completion and history and a powerful locals facility, and it even has (the beginnings of) a manual. Gforth employs traditional implementation techniques: its inner innerpreter is indirect or direct threaded. Gforth runs under Unix, Win95, OS/2, and DOS and should not be hard to port to other systems supported by GCC.
Bigloo is an implementation of the Scheme programming language. It relies on an optimizing compiler from Scheme to C. Bigloo enables connections between Scheme code and C code. It proposes many extensions to Scheme such as a regular parser compiler, an lalr parser compiler, pattern matching, an object layer, etc.
Octave is a high-level language, primarily intended for numerical computations. It provides a convenient command line interface for solving linear and nonlinear problems numerically, and for performing other numerical experiments. It may also be used as a batch-oriented language.
Excelsior JET is a Java VM enhanced with an Ahead-Of-Time (AOT) compiler and deployment toolkit. It is certified Java Compatible on Windows and Linux on Intel x86 hardware. The 64-bit version is in the works. Excelsior JET Optimizer transforms your classes and JARs into high-performance binary executables. Excelsior JET Runtime includes a licensed Sun implementation of the Java API and Excelsior's proprietary JVM, which is responsible for Java memory management, threading, synchronization, security, and JIT compilation of classes that could not be precompiled. The Excelsior JET Installation Toolkit makes it possible to prepare your optimized application for deployment to end-user systems.
JCPP is a complete, compliant, standalone, pure Java implementation of the C preprocessor. It is intended to be of use to people writing C-style compilers in Java using tools like sablecc, antlr, JLex, CUP, and so forth. It has been used to successfully preprocess much of the source code of the GNU C library.
pyPEG is a quick and easy solution for creating a parser in Python programs. pyPEG uses a PEG language in Python data structures to parse, so it can be used dynamically to parse nearly every context free language. The output is a plain Python data structure called pyAST, or, as an alternative, XML.
Cobra is a general purpose programming language with a clean, high-level syntax. It provides language level features for quality, including first class unit tests and Eiffel-style contracts. It supports both static and dynamic binding. Cobra is a compiled language with good run-time performance, but also provides some scripting conveniences such as a pound-bang line (#!) and one step compile-and-run. Cobra runs on Linux, Mac, Windows, and anywhere else that Novell Mono or MS .NET exist, including handhelds.