If you visit Google today, you will see a special logo that celebrates L. L. Zamenhof's 150th birthday. Zamenhof was born on December 15, 1859 and died on April 14, 1917. He is known as the inventor of Esperanto, a constructed language designed for international communication.
Here is Google's special Doodle for his birthday:
Google has a special page just searching for this language at google.com/intl/eo.
Zamenhof was Jewish and died in Warsaw, Poland. You can read his full bio at Wikipedia.
With almost all Google Doodles, there are always complaints. We have two Google Web Search Help threads. One is thanking Google for commemorating L. L. Zamenhof life, while the other is upset Google picked L. L. Zamenhof over the ratification of the U.S. Bill of Rights, which happened on December 15, 1791 (218 years ago).