If Ortelius is the father of the modern atlas, Diderot is the creator of the encyclopedia as we know it. His Encyclopédie sought to act as a reference work for useful human knowledge and is widely accepted as being the first modern encyclopedia. This work is considered one of the most important texts of the Enlightenment and was compiled by many contributors, known as Encyclopédists. Topics covered in the work included units of measurements, the Arts Mechaniques, agriculture, and many, many other topics.
The Encyclopédie was notable for many reasons. Not only did it create the modern encyclopedia as we know it, as well help move the ideas of the Enlightenment along, but it was also politically important. Some contributors openly attacked the Catholic Church and the French Monarchy (while others defended these institutions), and Clement XIII placed it on the Index. Despite Diderot's perception that, during his lifetime, the work was pointless, the Encyclopédie is now seen as one of the forerunners of the French Revolution.