Interlinguistics of interlinguistics are, however, not so constructive, but rather descriptive, comparative, historic, sociolinguistic, or concerned with translation by humans or machines. As for Esperanto, which is the most widely used constructed interlanguage, there is a relatively abundant literature about the language itself and its philology (see Esperantology). Only a few of the many constructed languages have been applied practically to any noteworthy extent. The most prosperous were Volapük (1879, Johann Martin Schleyer), Esperanto (1887 Ludwik Lejzer Zamenhof), Latino sine flexione (1903, Giuseppe Peano), Ido (1907, Louis Couturat), Occidental-Interlingue (1922, Edgar de Wahl) and Interlingua (1951, IALA and Alexander Gode), with
Ludwik Maciej Angeles, California. Ludwik Maciej had two sons, Sylwester and Luis, neither of whom were born in Poland. Ludwik Maciej died on March 12, 2007, in Los Angeles, California, and was buried on April 10, 2007, at the cemetery at Church of the Blessed Virgin Mary. With the help of Christians in Czechowice-Dziedzice, his ashes were brought from the USA by his son and buried in Ludwik Maciej's family grave at the cemetery. Ludwik Maciej Ludwik Maciej (May 16, 1915 – March 12, 2007) was a Polish military pilot, who participated in World War II. Son of Jan and Anna (née