[boost] multivariate polynomials

I noticed Boost.Math has some univariate polynomial-related functions, but I couldn't find anything regarding multivariate polynomials in either boost or the sandbox. It seems like something ripe for generic programming (hence I think of boost first). Is anyone currently working on something this, or can anyone provide a recommendation for an outside library? Our particular application deals with real (or complex) multivariate polynomials, and being able to do arithmetic, differentiation, integration, composition, and (of course) evaluation (among, perhaps, other operations). Thanks, - Jeff