Hypes and trends (such as Web ) cause a change in the requirements for user interfaces every now and then. While a lot of frameworks are capable of meeting those changing requirements, it often means you as a developer need in-depth knowledge of web standards, such as XHTML and JavaScript. A framework like Apache MyFaces that hides all details of how the page is rendered at the client and at the same time offers a rich set of tools and building blocks could save you a lot of time, not only when you’re building a brand new application but also.