Leonard Rosenthol is a Principal Scientist and PDF Architect for Adobe Systems, having been involved with PDF technology for more than 15 years. He represents Adobe on various international standards bodies including the ISO (where he is the Project Editor for PDF/A and PDF/E), W3C and ETSI/ESI (where he authored the PDF Electronic Signature standard, PAdES). Prior to re-joining Adobe in 2006, Leonard worked as the Director of Software Development for Appligent, and the Chief Innovation Officer for Apago, while also running the successful consulting business of PDF Sages. Before becoming involved in PDF, Leonard was the Director of Advanced Technology for Aladdin Systems and responsible for… the development of the StuffIt line of products.