According to the W3C consortium, XHTML knowledge is imperative to create a website. If you ar a beginner, here is a tool that might help you to learn this language in no time.
Web Design Toy is a program designed to allow you to learn XHTML code. With this tool, you can view the real time effect of what you are typing in the browser that is to say you type in the left pane of the interface and see, in the right pane, the result that the browser will display Web Design Toy is a totally free program that weighs only 500KB. Since it is portable, it does not require any installation.