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 Rajchman Ludwik Rajchman Ludwik Witold Rajchman (1 November 1881 – 13 July 1965) was a Polish physician and bacteriologist. He is regarded as the founder of UNICEF, and served as its first Chairman from 1946 to 1950. He was born to Aleksander Rajchman, the creator and first director of the Warsaw Philharmonic, and Melania Hirszfeld, a socialist and women's rights activist. He was from a family of Christianized Polish Jews. While the parents were agnostic, Ludwik was baptized at birth. He is the brother of Aleksander Rajchman, a prominent Polish mathematician and of Helena Radlinska, a Polish sociologist and he is