Original: The project was led by Udi Manber of Google , announced December 13 , 2007 , and was opened in beta to the public on July 23 , 2008 with a few hundred articles mostly in the health and medical field .
Simplified: The project was announced on December 13 , 2007 and opened in beta to the public on July 23 , 2008 . When it was opened , there were a few hundred articles mostly about health and medicine .