Recursively Enumerable Language
A Wikipedia article which defines Turing machines, gives examples and describes equivalent models and the universal Turing machine. Turing Machine Simulator
A simulator which runs included programs such as a palindrome detector and also allows writing of programs. Turing Machines
Article in Stanford Encyclopedia of Philosophy. Turing Machines and Computability
A discussion of decision problems, Turing machines, noncomputable problems, Goedel numbering and the halting problem. Turing Machine Languages
This article shows the relation between recursively enumerable languages and Turing machines.