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.
Roadsend PHP produces optimized stand alone applications, libraries, and Web applications from standard PHP source code. The compiler produces native machine code, not PHP byte code, so no interpreter is required. It is a new implementation of the PHP language and runtime environment compatible with Zend PHP. It does not share any code with the original PHP implementation.
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.
A+ is a powerful and efficient programming language. It embodies a rich set of functions and operators, a modern GUI with many widgets and automatic synchronization of widgets and variables, asynchronous execution of functions associated with variables and events, dynamic loading of user compiled subroutines, and many other features. Execution is by a rather efficient interpreter.
"C Server Pages" is a C++ application server. It runs server pages written in HTML with C++ embedded and templates with C++ beans. It features scalability and integration with the backend, multiprocess and multithread functionality, and it is tunable, load balancing, and behaves well even when highly loaded.