Depends on what you mean by "using". Writing it, probably not so much. But a lot of the numerical things I use are written in Fortran (e.g. BLAS, Atlas). A lot of games I play probably have some hand optimized Assembly. And pretty much everything I touch is in some way backed by C. For natural language processing I've recently (re)discovered how useful PROLOG can be in some cases, and I may touch on that this year.