Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In theoretical computer science a pointer machine is an "atomistic" abstract computational machine model akin to the Random access machine. Depending on the type, a pointer machine may be called a linking automaton, a KU-machine, an SMM, an atomistic LISP machine, a tree-pointer machine, etc. At least three major varieties exist in the literature - the Kolmogorov-Uspenskii model, the Knuth linking automaton, and the Schönhage Storage Modification Machine model. The SMM seems to be the most common.