Rich, interactive web applications AKA fat clients are now commonplace. There are so many frameworks for building these rich client applications, and the debate among developers is which of these frameworks to use. As designers and developers we need to step back, and ask ourselves when and how we should enrich our client applications and when or why not. Let's dig in to the question: Why do we even want fat clients, and when should we use them? Let's examine the complications such clients introduce so we can weigh them against all the benefits.