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.
GPP is a general-purpose preprocessor with customizable syntax, suitable for a wide range of preprocessing tasks. Its independence from any programming language makes it much more versatile than cpp, while its syntax is lighter and more flexible than that of m4. The syntax is fully customizable, which makes it possible to process text files, HTML, or source code equally efficiently in a variety of languages.
The Objex Project (like the GNU Project) aims to develop a complete operating system composed of free and open source software. In contrast to the GNU Project, it aims to build a modern system that brings together all the recent advances in computer science, instead of a Unix-like system. "A complete system" means that it will include the kernel, a full suite of developers tools, user utilities, and a graphical user interface. It is based on OSKit, a framework and a set of utilities, drivers, and program code intended for operating system creation.
Logtalk is an object-oriented logic programming language that can use most Prolog implementations as a back-end compiler. As a multi-paradigm language, it includes support for both prototypes and classes, protocols (interfaces), component-based programming through category-based composition, event-driven programming, and high-level multi-threading programming.
TCLP is a type checker for Prolog dialects. It is written in SICStus Prolog. Its goal is to statically trap programming errors like illegal arguments used in a call for a predicate or illegally built data structures with respect to a given typing for function symbols or predicates. TCLP is also capable of type inference for user predicates. Supported dialects include ISO-Prolog, GNU-Prolog, and SICStus Prolog.
SHORE (Semantic Hypertext Object Repository) is a hypertext repository that stores data about documents and data described by documents. Access to this information is provided as hypertext. The repository stores objects that appear in documents, together with their relations in a semantic net. Hypertext navigation follows these relations in the semantic net. The SHORE server works as an HTTP server, and the client is a standard Web browser. The repository uses PROLOG as its query language and the XSB system as its query engine.
DELORES (DEfeasible LOgic REasoning System) is a forward-chaining reasoning engine for defeasible logic, a less-expressive but more efficient non-monotonic logic. In contrast with most other non-monotonic logics, defeasible logic has linear complexity, allowing DELORES to execute large theories very quickly. DELORES's algorithm extends to general defeasible theories through the use of a pre-processing transformation which eliminates all uses of defeaters and superiority relations.
YProlog is a pocket Prolog engine written in 100% Java. It provides a number of fast and easy Java-Prolog interfacing functions that enables the Prolog database to be used like an SQL-type database. It has fast consult and retract operations, can "serialize" database contents into text, and can easily load and store tables or contents of Java objects. It is based on Jean Vaucher's XProlog.