Mathematics Archives
Math Archives: Composition of Functions
Site offers a detailed explanation of the compostion of functions
Wolfram Research
Wolfram Math World: Composition
A definition of composite functions and an investigation of their use in combinatorial compositions.
University of Saskatchewan (Canada)
University of Saskatchewan: Composition of Functions
This unique site allows one to enter two functions from a list of options, graphs both functions and their composition, then allows the user to trace any of the three via the java applet.