{An \XML\ model of \CSS3 as a X\LaTeX-\TeX\ML-\HTML5 stylesheet} {Sukumar Sankar, S~Mahalakshmi and L~Ganesh} {\HTML5 and \CSS3 are becoming the popular language of choice in the web. However, quite like \HTML, \CSS\ is prone to errors and difficult to port, so we propose an \XML\ version of \CSS\ that can be used as a standard for creating stylesheets and templates across different platforms and pagination systems. X\LaTeX\ and \TeX\ML\ are some examples of \XML\ that are close in spirit to \TeX\ that can benefit from such an approach. Modern \TeX\ systems like \XeTeX\ and \LuaTeX\ use simplified \code{fontspec} macros to create style sheets and templates. We use \XSLT\ to create mappings from this \XML-style sheet language to \code{fontspec}-based \TeX\ templates and also to \CSS3. We also provide user friendly interfaces for the creation of such an \XML\ style sheet. }