I’m currently browsing PlanetMath using the new ”eww” browser for Emacs. It’s very simple and I’m relatively sure that it won’t handle MathML well at all. For instance, it might know what to do with $X+Y$ and possibly even $\alpha$, but it’s bound to get confused by $\int_{x}^{{\infty}}e^{{-x^{2}}}\>dx$. However, maybe we can contribute to its improvement in this regard. At the moment, I’m just pleased that I was able to log into PlanetMath and (hopefully) post this.