ACL2 is a mathematical logic, programming language, and mechanical theorem prover based on the applicative subset of Common Lisp.
a complete Prolog system, supporting ISO-Prolog, but its novel modular design allows both restricting and extending the language. As a result, it allows working with fully declarative subsets of Prolog and also to extend these subsets (or ISO-Prolog) both syntactically and semantically
a high-level programming language combining constraint inference with concurrency
(commercial) an advanced Prolog engineering tool for use in industrial and commercial environments. IF/Prolog has a rich set of interfaces to other standard software components and an additional Constraint Technology Package for efficient solutions of complex optimization problems
a logic-based programming language and a tool that translates programs, that is, formulas, to finite-state automata
implements Oz, a concurrent object-oriented language with dataflow synchronization. Oz combines concurrent and distributed programming with logical constraint-based inference, making it a unique choice for developing multi-agent systems
o42a is a high-level general purpose programming language. It is compiled, statically-typed, prototype-based, logic-driven, and primarily declarative, while the imperative programming style is also supported.
a high-level programming language combining constraint inference with concurrency. Typical application areas of Oz include optimization problems like scheduling, time tabling, placement and configuration, reasoning and knowledge representation, processing of natural language, simulations, multi agent systems, and sophisticated graphical user interfaces
Picat is a simple, and yet powerful, logic-based multi-paradigm programming language aimed for general-purpose applications. Picat is a rule-based language, in which predicates, functions, and actors are defined with pattern-matching rules.
(commercial) a Prolog Development System. SICStus Prolog conforms to the ISO Prolog standard. It is built around a high performance Prolog engine