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.
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.
ConceptBase is a multi-user meta-database system based on a deductive object manager. It is mainly intended for conceptual modeling and coordination in design environments. The system implements O-Telos, a dialect of Telos that amalgamates properties of deductive and object-oriented languages.
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.