This is a lecture note on regular differential equations, edited by A. Dold and B. Eckmann. The work is authored by Pierre Deligne, a French mathematician based at the Institute for Advanced Scientific Studies in Bures-sur-Yvette. The book is published by Springer-Verlag in 1970 and is available in the United States through the Library of Congress. The book is divided into three main parts: an introduction, a dictionary, and applications. The dictionary section provides definitions and explanations of key concepts in the field of differential equations, including local systems, integrable connections, and partial differential equations. The second part discusses regular connections, covering topics such as regularity in one and n dimensions, existence theorems, and comparison theorems. The third part presents applications of the theory, including functions of Nilsson class and the monodromy theorem according to Brieskorn. The book is intended for researchers and advanced students in mathematics, particularly those working in the field of differential equations and algebraic geometry. The work is a comprehensive resource on the theory of regular differential equations, with a focus on the structure and properties of such equations. The book is also available in French, with a detailed table of contents.This is a lecture note on regular differential equations, edited by A. Dold and B. Eckmann. The work is authored by Pierre Deligne, a French mathematician based at the Institute for Advanced Scientific Studies in Bures-sur-Yvette. The book is published by Springer-Verlag in 1970 and is available in the United States through the Library of Congress. The book is divided into three main parts: an introduction, a dictionary, and applications. The dictionary section provides definitions and explanations of key concepts in the field of differential equations, including local systems, integrable connections, and partial differential equations. The second part discusses regular connections, covering topics such as regularity in one and n dimensions, existence theorems, and comparison theorems. The third part presents applications of the theory, including functions of Nilsson class and the monodromy theorem according to Brieskorn. The book is intended for researchers and advanced students in mathematics, particularly those working in the field of differential equations and algebraic geometry. The work is a comprehensive resource on the theory of regular differential equations, with a focus on the structure and properties of such equations. The book is also available in French, with a detailed table of contents.