Complex sentence: In 2003, Working with in partnership with publisher Tim O'Reilly, Battelle founded what is now known as the Web 2.0 Summit, calling "this grandfather of Internet conferences" among his "proudest editorial works".
Split into simpler sentences: In 2003, Battelle and publisher Tim O'Reilly founded what is now known as the Web 2.0 Summit. Battelle called "this grandfather of Internet conferences" among his "proudest editorial works".