Matjito is a pluggable library for the rapid computation of mathematical expressions in C++ programs. Its accepts either an expression string with information about the mapping of symbols to variables and functions or an n-ary tree representing the expression. It features an x86 JIT that allows expressions to be computed very quickly, and is comparable or even better than code generated by optimizing C compilers. It can be used on non-x86 CPUs in a slower interpreting mode. (Source: