Esperantido

Ido () is a constructed language derived from a reformed version of Esperanto, and designed similarly with the goal of being an international auxiliary language (or universal second language) for people of diverse languages. To function as an effective international auxiliary language, Ido was designed specifically to be grammatically, orthographically, and lexicographically regular (and, above all, easy to learn and use). It is the most successful of the many Esperanto derivatives, known as Esperantidoj.

An Esperantido (plural Esperantidoj) is a constructed language derived from Esperanto. Esperantido originally referred to the language which is now known as Ido. The word Esperantido contains the affix (-ido), which means a "child (born to a parent), young (of an animal) or offspring". Hence, Esperantido literally means an 'offspring or descendant of Esperanto'. The term was coined by Claus Killing-Günkel.

Adjuvilo is a constructed language created in 1910 by Claudius Colas under the pseudonym of "Profesoro V. Esperema". Although it was a full language, it may not have been created to be spoken. Many believe that as an Esperantist, Colas created Adjuvilo to help create dissent in the then-growing Ido movement. Colas himself called his language simplified Ido and proposed several reforms to Ido.

constructed language based on Esperanto, aimed at a deliberately medieval feel as a hypothetical earlier stage of Esperanto

Esperantido

Mundolinco is a constructed language created by the Dutch author J. Braakman in 1888. It is notable for apparently being the first Esperantido, i.e. the first Esperanto derivative, published the year after Esperanto was introduced in the Unua Libro.

Esperanto reform of 1937

constructed language based on Esperanto