The Esperanto flag was adopted by the first World Esperanto Congress in 1905. The green star (verda stelo) was purposed early on and adopted into the Esperanto flag. The green of the flag represents hope; the white area represents peace and neutrality; and the 5 point star represents the 5 continents of Europe, Asia, Americas, Africa, and Oceania.
The Esperanto Jubilee Symbol (jubilea simbolo) was created in 1987 to mark the 100th anniversary of Esperanto. It was constructed from two E's: the Latin E on one side (representing the West) and a Cyrillic Э (for Эсперанто which is Russian for 'Esperanto') on the right side.
On December 15th, 2009 Google added an Esperanto Flag in their logo on search result pages to celebrate L. L. Zamenhof's 150th birthday.