The current volume constitutes the proceedings of the International Conference in Algebraic Topology, held on the Isle of Skye, Scotland in June 200l. Many of the the talks at the conference focused on categorical decomposition techniques currently used in algebraic topology, such as Goodwillie's "calculus of functors" and the various approximation techniques that have proved so useful for the study of classifying spaces. The contents represent these, and other themes in algebraic toplogy, as they are being developed by experts in the field. For instance, the homotopy theory of classifying spaces is represented by the articles of Aguade-Broto-Saumell, Davis and Iwase-Mimura. The papers by Betley, Kuhn and Panov-Ray-Vogt deal with general categorical decomposition techniques. The papers of Anton, Goerss-Henn Mahowald and Hodgkin-Ostvaer bring us to the forefront of computational homo topy theory. Other papers deal with assorted topics of current interest in algebraic topology. Progress in Mathematics, Vol. 215 Algebraic Topology: Categorical Decomposition Techniques, 1-20 (c) 2003 Birkhiiuser Verlag Basel/Switzerland The Functor T and the Cohomology of Mapping Spaces Jaume Aguade, Carles Broto, and Laia Saumell 1. Introduction In his fundamental work 15] Lannes has introduced a functor T defined in the category K (resp. U) of unstable algebras (resp. modules) over the Steenrod algebra which has many important applications in homotopy theory. This functor is, in some sense, the algebraic analogue of the mapping space functor Map(BV, -) for an elementary abelian group V."

The book consists of articles at the frontier of current research in Algebraic Topology. It presents recent results by top notch experts, and is intended primarily for researchers and graduate students working in the field of algebraic topology. Included is an important article by Cohen, Johnes and Yan on the homology of the space of smooth loops on a manifold M, endowed with the Chas-Sullivan intersection product, as well as an article by Goerss, Henn and Mahowald on stable homotopy groups of spheres, which uses the cutting edge technology of "topological modular forms."