Though Esperanto itself has changed little since the publication of the Fundamento de Esperanto (Foundation of Esperanto), a number of reform projects have been proposed over the years, starting with Zamenhof's proposals in 1894 and Ido in 1907. Several later constructed languages, such as Fasile, were based on Esperanto.
In modern times, attempts have been made to eliminate perceived sexism in the language. One example of this is Riism. However, as Esperanto has become a living language, changes are as difficult to implement as in ethnic languages.