For four decades, the Cyc project has been working on giving machines the ability to reason. To this end, researchers have built a vast knowledge network consisting of millions of concepts and rules. Cyc can draw conclusions, answer questions, and even reconcile conflicting information from different domains. Despite these impressive achievements, Cyc is largely forgotten today. New approaches based on machine learning have revolutionized AI research. But the Cyc project is not giving up, and is looking for ways to combine its strengths with those of systems like ChatGPT. Whether the time of rule-based systems like Cyc will return remains to be seen.