So I've recently been getting into front-end web development from an embedded systems background and have always thought Javascript/HTML/CSS are not only the de-facto standards but the ONLY tools for the job, similar to what C is for embedded systems. Recently, I've stumbled upon things like Dreamweaver, JSP, facelets, and GWT. While researching these to find out if they are worth learning, I can't get over the idea of why someone wouldn't just use Javascript/HTML/CSS instead. Why deviate from the defacto standards?