Search engine giant Google turned 23 years old on Monday. Marking the special occasion, the company unveiled a special cake-themed doodle on its homepage. The animated doodle features a cake with "23" written on top of it, with a birthday candle indicating "L" in "Google". Google was founded by Larry Page and Sergey Brin in September 1998, as part of a PhD project. The two ideated the firm in 1995. By 1996, they had reportedly built a search engine, initially called 'BackRub', that used links to determine the importance of individual web pages.