Many Esperantists believe this declaration stabilising the language is a major reason why the Esperanto speaker community grew beyond the levels attained by other constructed languages and has developed a flourishing culture. Other constructed languages have been hindered from developing a stable speaking community by continual tinkering. Also, many developers of constructed languages have been possessive of their creation and have worked to prevent others from contributing to the language. One such ultimately disastrous case was Schleyer's Volapük. In contrast, Zamenhof declared that "Esperanto belongs to the Esperantists", and moved to the background once the language was published, allowing others to share in the early development of the language.