Finite State Machines (FSM)
http://ai-depot.com/FiniteStateMachines/FSM.html
Finite State Machine Emulators
http://courses.cs.vt.edu/~cs1104/FSM/FSM.Overview.html
Finite State Machine Design
http://www2.ele.ufes.br/~ailson/digital2/cld/chapter8/chapter08.doc.html