XHTML stands for Extensible Hyper Text Markup Language. HTML is somewhat messy, and there are very few rules that all pages follow. This leads to confusion when beginners are trying to learn the language. Furthermore, since different browsers (such as Opera, Firefox, and Internet Explorer) interpret HTML differently, certain pages look different when viewed with different browsers. XHTML aims to fix this; it transforms HTML into a language that follows somewhat stricter guidelines. This makes it clearer and easier to learn and implement.
• XHTML Syntax Rules
• XHTML Modularization
• XHTML Standard Attributes