Comparison between Esperanto and Ido Ido was satisfied with it. Many former Idists, such as Otto Jespersen (who created Novial) left the movement, bleeding Ido of leaders. Of all synthetic auxiliary languages, only Esperanto and Interlingua-IL de ApI gained a sizeable following and textual corpus to this day. Esperanto is based on the "Fundamento de Esperanto" by L. L. Zamenhof; whereas the grammar of Ido is explained in the "Kompleta Gramatiko Detaloza di la Linguo Internaciona Ido". Since Esperanto has proved to be a living, stable language, nowadays Esperantists are less quick to reject influences from Ido. Probably the most fundamental of these is that
Ludwik Birkenmajer of scholars. He was married Zofia (Sophie), the daughter of Franciszek Karliński, the professor of astronomy in the Jagiellonian University, and inherited his library embracing mostly the books on mathematics and physics. They had three sons: Aleksander Ludwik (historian of culture and exact sciences, and bibliologist), Józef (poet, interpreter and literature historian), and Wincenty (Polish philologist, teacher and renown Tatra Mountains-climber). His grandson is Krzysztof Birkenmajer (professor of geology, member of the Polish Academy of Sciences). In 2011 the Institute for the History of Science of the Polish Academy of Sciences received the name of father and son: Ludwik &