Cerf's defection from MCI Inc., announced Thursday, represents the latest coup for Mountain View-based Google, which has been amassing more brainpower as its payroll nearly quadrupled to 4,200 workers during the past two years.
Along the way, Google has been raiding other companies, a tactic that has sparked a legal battle with one of its major rivals, software maker Microsoft Corp. The two high-tech titans battled in court this week over Kai Fu-Lee's July resignation from Microsoft to oversee Google's efforts to open a research center in China.
In an interview, Google chief executive Eric Schmidt said few of the company's recent hires have been as significant as Cerf, widely regarded as one of the Internet's creators because of his seminal work developing the network's essential communications protocols, TCP/IP, at Stanford University in the 1970s.
"He is one of the most important people alive today," said Schmidt, who has been friends with Cerf for more than 20 years. "Vint has put his heart and soul into making the Internet happen. I know he is going to jump right in here and start shoveling out new ideas for Google."
When he starts work at Google on Oct. 3, Cerf's official title will be "chief Internet evangelist," but he is determined to be more than a figurehead or detached visionary.
"What I have done in the past is not going to be important at Google," Cerf said during an interview. "What's important at Google is what you are doing today and what you going to do tomorrow. That's the metric I will be measured by."
Cerf will remain chairman of the Internet Corporation for Assigned Names and Numbers, the oversight agency for Internet domain names.
He also will continue as a visiting scientist at NASA's Jet Propulsion Laboratory, where he has been focusing on a very Google-like project -- trying to figure out a way to connect the Internet to outer space.