Homaranismo (roughly: "Humanitarianism" or "Humanitism") is an Esperanto word used by its creator, Ludwig Zamenhof, to describe his philosophy of human interaction and behaviour. Based largely on the teachings of Hillel the Elder, a 1st century BCE rabbi, Zamenhof originally called this philosophy Hillelism. Firstly he only want to reform Judaism, because he hoped that Judaism without the strange dress code and purity requirements would not longer be the victim of antisemitic propaganda. The basis of Hillelism is the sentence with which you could, so Hillel, abstract the whole bible. This sentence is called the Golden Rule: One should treat others as one would like others to treat oneself.
Zamenhof says about it:
With Hillelism we don't mean a new denomination, we mean a new corporate-religious order inside the old jewish religion, which exists for a long time. Everybody who lives ethical could take part in this religion with a clear conscience, however his religious views he had before, look like. This base brought him the idea that this philosophy could be a bridge between the religions. So he renamed it into Homaranismo.
Zamenhof first described this philosophy around the year 1900 and published it anonymously in a brochure in 1906. He later published a revised version in 1913 under the name Homaranismo.
While many different motivations drew early Esperantists to that movement, for Zamenhof Esperanto was always a means by which to facilitate improved human relations, especially beyond boundaries of race, language and culture. Zamenhof's daughter Lidia embraced this philosophy and taught it alongside Esperanto, and her adopted religion, the Bahá'í Faith.
Doctrine and cult of the Homaranismo have many similarities to the civil religions of the French Revolution, mostly to the Theophilanthropy
The symbole of the Homaranismo is a green star, which looks like the green star of Esperanto.
Note: This article was adapted from the German Wikipedia article