Google marks 28th birthday with retro Doodle

Google is observing its 28th anniversary today with a nostalgic homepage Doodle that displays the company's original 1998 logo and an interactive historical trivia quiz. The celebration highlights the journey from a Stanford research project called BackRub to the world's dominant search engine.

Although Google Inc. was formally incorporated on September 4, 1998, after a $1 million investment from Andy Bechtolsheim, the company has marked its birthday on September 27 since 2006. That date commemorates the announcement of the largest expansion of Google's web search index at the time, which gave it a processing edge over rivals and led to the removal of the page counter from the homepage.

The name Google originated from a spelling error. Founders Larry Page and Sergey Brin intended to name the service after the mathematical term Googol, representing one followed by 100 zeros. When a student mistyped the domain search as Google, the founders kept the mistake.

Google's early advantage came from PageRank, which used links between pages as a relevance signal, and a minimalist interface focused on speed. Over the years the service expanded beyond the classic ten blue links to include image and news search, local results, and mobile adaptation.