Ciao is a complete Prolog system subsuming ISO-Prolog with a novel modular design which allows both restricting and extending the language. Ciao extensions currently include feature terms (records), higher-order, functions, constraints, objects, persistent predicates, a good base for distributed execution (agents), and concurrency. Libraries also support WWW programming, sockets, and external interfaces (C, Java, TCL/Tk, relational databases, etc.). An Emacs-based environment, a stand-alone compiler, and a toplevel shell are also provided.
interpcom is a command interpreter library in C that can be used to build scientific applications. It is very easy to add new commands. The library contains an expression evaluator that can be used to parse the arguments of the commands. It is possible to define "objects" which are arrays of numbers having a name, and structures. It is possible to use threads (several programs running simultaneously).
Mercat is a light-weight, cross platform programming language. It is garbage collected and self hosting and produces portable byte-compiled binaries that can be executed on any platform with the appropriate interpreter. Interpreters are available for Linux, DOS (32-bit) and DOS (16-bit) and the interpreter source should be easily compilable for other platforms.
Pike is an interpreted, object-oriented, dynamic programming language with a syntax similar to C. It includes a powerful modules system that, for instance, has image manipulation, database connectivity and advanced cryptography. It is simple to learn, does not require long compilation passes and has powerful built-in data types allowing simple and fast data manipulation.
ScriptBasic is an interpreter for the old language BASIC. It runs on Win32 as well as on UNIXes as a command-line or CGI program interpreter. It includes an interpreter, a compilable, well-documented embedding and extending interface for the C programmer, and a rich set of commands and functions.
Styx is a scanner/parser generator designed to address some shortcomings of the traditional lex/yacc combination. It has unique features like automatic derivation of depth grammar, production of the derivation tree, including it's C interface, preservation of full source information, pretty printing to faciliate source-source translation, and persistence to aid rapid interpreter writing. It also supports reentrancy. Styx works well under several different OSes, including serveral Unixes, DOS, and Windows.