The document compares and contrasts several rich internet application platforms: Adobe Flex, Microsoft Silverlight, and JavaFX. It provides code examples and summaries of the key features for each platform. Flex is the most mature with a large ecosystem but high learning curve. Silverlight has fewer components than Flex but integrates well with .NET. JavaFX has potential but lacks components and tooling is not as developed as Flex or Silverlight. The document advocates developing rich clients across platforms using a single Eclipse installation.