Believe it or not, Esperanto has a deep literature all its own. While most of the literature one finds in Esperanto consists of translations of works written in other languages, such as the free etexts available on gutenberg.org, a respectable number of authors have taken to writing original Esperanto works. Luckily, their numbers grow all the time!
One of the most famous Esperanto works is “Gerda Malaperis,” by French author Claude Piron (Incidentally, “piro” in Esperanto means “pear”). Gerda Malaperis is a mystery-style story told primarily through dialogue rather than narrative. Piron relates the tale using progressively more advanced vocabulary, so the book begins using simple Esperanto, and concludes using diction that reveals some of the subtler aspects of the Esperanto language. As such, Gerda Malaperis appears in many Esperanto courses, and serves as great introductory material for anyone seriously interested in studying Esperanto.
(aperi = to appear.)
The tuta teksto of Gerda Malaperis can be found here.