Puppeteer is a system for adapting component-based applications in mobile environments. Puppeteer takes advantage of the component-based nature of the applications to perform adaptation without modifying the applications. We illustrate the power of Puppeteer by demonstrating adaptations that would otherwise require significant modifications to the application. Our initial prototype supports Microsoft PowerPoint and Internet Explorer~5 without requiring any changes to the applications. It supports delayed data and image transmission as well as progressive image refinement. We measure our system's effectiveness with a large number of PowerPoint documents and Web pages. We measure user-perceived latencies for a variety of adaptation policies and over a variety of different network bandwidths. Our results show that Puppeteer can achieve average reductions in user latency of up to 84.22% for PowerPoint documents loaded over a 384~Kb/sec link and 76.42% for HTML documents loaded over 56~Kb/sec link.