The regular open-open topology, Troo, is introduced, its properties for spaces of
continuous functions are discussed, and Troo is compared to Too, the open-open topology. It is then
shown that Troo on H(X), the collection of all self-homeomorphisms on a topological space, (X,T),
is equivalent to the topology induced on H(X) by a specific quasi-uniformity on X, when X is a
semi-regular space.