The document discusses why Scala is a good language choice for Web 2.0 applications. It provides a brief history of languages used for Web development and introduces Scala as a functional, object-oriented language that runs on the JVM. The document outlines several features of Scala like actors for concurrency, type inference, and pattern matching that make it suitable for building scalable web applications. It also discusses the Scala community and various tools and libraries available that help develop and test Scala applications.