Logtalk is an Open-Source, object-oriented logic programming language that extends and leverages the Prolog language with a feature set suitable for programming in-the-large.

Logtalk supports modern code encapsulation and code reuse mechanisms without compromising the declarative programming features of Prolog. Logtalk is implemented in highly portable code and can use most modern and standards compliant Prolog implementations as a back-end compiler. The Logtalk distribution features portable libraries and portable assertions, documenting, diagraming, and unit testing tools, plus extensive code editing and publishing support. It also includes extensive documentation and a large number of programming examples.