Overview of Prolog: Why Startups and AI Developers Should Learn It Today

When the conversation turns to programming languages, most people recall Python, JavaScript, or C++. But there is a language that has existed for over half a century and still surprises with its uniqueness — Prolog. It emerged in the 1970s as a tool for creating artificial intelligence systems and logical reasoning.

Prolog is a logic programming language in which the developer describes not a sequence of actions, but facts and rules that define truth. Instead of long instructions, a knowledge base is created: statements about the world and logical connections between them.

What makes it unique
Prolog operates on the principles of unification and backtracking. Unification matches variables and values, attempting to find a logical match. Backtracking automatically goes back and searches for other options if a solution is not found. This mechanism makes Prolog one of the few languages where the program itself searches for an answer, relying on facts and logic.

Prolog is unlike familiar languages: here you need to think declaratively, describing what is true rather than what to do. It is ideally suited for:
— expert systems
— natural language processing
— reasoning models
— logical and explainable AI applications.

Today, interest in Prolog is reviving. The reason is the growing popularity of explainable AI and hybrid models, where logic is combined with neural networks. Developers are looking for ways to make AI not only powerful but also understandable. In this regard, Prolog finds itself once again at the forefront.

Useful resources
Despite its age, Prolog has an active community and modern tools.

The most popular implementation is SWI-Prolog. This is an open environment with libraries, documentation, and support for integrations with Python, C, and web technologies.

For self-study, the following resources are suitable:

Learn Prolog Now! — an interactive textbook created with the support of SWI-Prolog developers. Excellent for getting started.

The Power of Prolog — a modern guide by Markus Triska, which helps understand the philosophy of the language and learn to write "clean" code.

TutorialsPoint: Prolog — a concise reference on syntax and basic concepts.

Online courses
If you want to study Prolog systematically, try free courses and lectures:

Best Free Prolog Courses on Class Central — a selection of programs from the University of Edinburgh and other platforms.

SWI-Prolog Tutorials on the official website — short step-by-step practical exercises.

University of Toronto — Prolog Lecture Notes PDF — a concise academic introduction.

Video course "Prolog in AI" on YouTube — an introduction to logic, examples of expert systems, and NLP tasks.