category theory, taken from Kurz homepage:
M. Caccamo, J.M.E. Hyland, G. Winskel:
Lecture Notes
in Category Theory. BRICS Lecture Series, 2001.
M. Fokkinga:
A Gentle Introduction to Category Theory - the calculational
approach. University of Utrecht, 1992.
Chris Hillman: A
Categorical Primer. August 2001.
Tom Leinster:
Category Theory.
This page contains an informal
introduction to category theory and, for example, a nice explanation
of the Yoneda Lemma.
Jaap van Oosten:
Basic Category Theory.
D. Turi: Category
Theory Lecture Notes. LFCS, Univeristy of Edinburgh, 2001.