You can build Web 2.0 applications using GeneXus. This page introduces features that will help you build them. Only the features that are highly-related to web development are listed here.
Take a look at these live samples to understand what we are talking about when we refer to usable interactive applications, applications that are built paying attention to design details.
If you are new to web environments, read Web Applications Basic Concepts for a quick update on this technology and its elements.