Currently, he is focusing on improving runtime performance. Previously, he led the design of the MXML language, and he helped create the Flex application model. Prior to joining the Flex team, he was an engineering lead for the first five releases of Macromedia Dreamweaver. Before joining Macromedia, he built a multimedia runtime engine for Sybase, and he created a 3-D photorealistic renderer for Digital Equipment Corporation. Over the last 15 years, he has created four timeline editors; he's hoping to avoid ever creating a fifth.