  Modern computational chemistry has reached a stage at which massive
exploration into chemical reaction space with unprecedented resolution with
respect to the number of potentially relevant molecular structures has become
possible. Various algorithmic advances have shown that such structural
screenings must and can be automated and routinely carried out. This will
replace the standard approach of manually studying a selected and restricted
number of molecular structures for a chemical mechanism. The complexity of the
task has led to many different approaches. However, all of them address the
same general target, namely to produce a complete atomistic picture of the
kinetics of a chemical process. It is the purpose of this overview to
categorize the problems that are to be targeted and to identify the principle
components and challenges of automated exploration machines so that the various
existing approaches and future developments can be compared based on
well-defined conceptual principles.
