{Unicode mathematics in \LaTeX: Advantages \programrlap{and~challenges}} {Will Robertson} {Over the last few years I've been tinkering with Unicode mathematics in \XeTeX. In late 2009 I spent a few weeks ironing out the significant bugs and think I've got a pretty good handle on the whole system now. In this presentation, I'll discuss the advantages Unicode maths brings to \LaTeX, challenges faced dealing with Unicode, challenges with maths fonts (including the \STIX\ fonts), challenges with compatibility with \pkgname{amsmath} and/or \MathML, and assorted related remarks. In future plans, I hope to use this system as the basis for equivalent development in Lua\TeX\ as well.}