  This book provides an inviting tour through sheaf theory, from the
perspective of applied category theory and pitched at a less specialized
audience than is typical with introductions to sheaves. The book makes it as
easy as possible for the reader new to sheaves, by motivating and developing
the theory via a broad range of concrete examples and explicit constructions,
including applications to n-colorings of graphs, satellite data, chess
problems, Bayes nets, musical performance, complexes, and more. Included is an
extended first chapter introducing and motivating all the necessary
category-theoretical background, again with a strong emphasis on concrete
examples.
  A new and unabridged version (including a fifth chapter on more advanced
topics and a conclusion) will be available with MIT Press.
