Rational homotopy theory is a subfield of algebraic topology. It has been an active area for more than 30 years, and no attempt has been made at writing a textbook in more than 15 years. Both notation and techniques of rational homotopy theory have been considerably simplified over the past 15 years, so that the older books in are already out of date. All three authors are considered to be among the leading experts in rational homotopy theory.
From the reviews:
MATHEMATICAL REVIEWS
"In 535 pages, the authors give a complete and thorough development of rational homotopy theory as well as a review (of virtually) all relevant notions of from basic homotopy theory and homological algebra. This is a truly remarkable achievement, for the subject comes in many guises."
Y. Felix, S. Halperin, and J.-C. Thomas
Rational Homotopy Theory
"A complete and thorough development of rational homotopy theory as well as a review of (virtually) all relevant notions from basic homotopy theory and homological algebra. This is truly a magnificent achievement . . . a true appreciation for the goals and techniques of rational homotopy theory, as well as an effective toolkit for explicit computation of examples throughout algebraic topology."
―AMERICAN MATHEMATICAL SOCIETY