Second language instruction in the U.S. and Europe is in difficulties. The choice of a second language is artibrary and the motivation dubious. In Europe and now also in the U.S., attention has turned to the planned interlanguage Esperanto, which offers a maximally regularized structure, is considered "easy" by learners, and has the motivational factor of politicoethnic neutrality. Bernsteinian educational reformers in Germany have suggested the adoption of Esperanto, which appears only to have an elaborated code, to help extend the linguistic repertoire of pupils whose native German is largely the elaborated code. The morphology, syntax and especially orthography of Esperanto are also a more useful introduction to general language principles than the complex, aberrant, atypical English and French. Recent and current experiments in Europe and proposed experiments in the U.S. are described here. The subject is of significance for second language acquisition theory, learning motivation, and language pedagogy. (Author/KM)