Google, the web giant is celebrating its 21st birthday on Friday with a retro Doodle. The Doodle shows you what a typical desktop computer looked like 21 years ago when Stanford Ph.D. students and Google co-founders Sergey Brin and Larry Page published a paper called The Anatomy of a Large-Scale Hypertextual Web Search Engine. In it, the pair outlined Google, a prototype “large-scale search engine” that had a database of “at least 24 million pages.” “We chose our system name, Google, because it is a common spelling of googol, or 10100, and fits well with our goal of building very large-scale search engines,” the pair wrote in the paper’s introduction. In the 21 years since Brin and Page outlined their vision for a search engine, the company has grown up dramatically. Google’s search engine now indexes hundreds of billions of webpages, but the company has gone from humble beginnings as a search engine to the most dominant force in advertising. Google now has a parent company, Alphabet, with tentacles that touch everything from self-driving cars to its Android mobile software to the extension of life.