Los Angeles-based OpenX. the developer of online ad serving software, said today that it has named Eric Rosenthal as the firm's General Manager of its Enterprise business. Rosenthal was previously at AOL, serving as VP of National Sales. Rosenthal also has previously served at DoubleClick, Kyte, Verizon, and Panther CDN/CDNetworks OpenX is backed by Accel Partners, Index Ventures, SAP Ventures, AOL Ventures, Mitsui & Co., Presidio Ventures and O'Reilly AlphaTech Ventures.