See http://www.cs.sunysb.edu/~algorith/files/network-flow.shtml for a discussion of the network flow problem and links to implementations of various algorithms that solve the problem.

An animation of the maximal flow algorithm is at http://www-b2.is.tokushima-u.ac.jp/~ikeda/suuri/index.html (select Ford-Fulkerson).

See http://www.cut-the-knot.com/arithmetic/elegant.html for more information and for a simulation of W. McWorter’s algorithm that solves the Marriage Problem.