T-diagrams were first introduced for describing bootstrapping and cross-compiling compilers by McKeeman et al. in 1971.[2] Melvin Conway described the broader concept before that with his UNCOL in 1958, to which Bratman added in 1961.[3] Later on, others, including P.D. Terry, gave an explanation and usage of T-diagrams in their textbooks on the topic of compiler construction.[3] T-diagrams are also now used to describe client-server interconnectivity on the World Wide Web.[4] A teaching tool TDiag has been implemented at Leipzig University, Germany.[5]