XMLMath

XMLMath is a program that evaluates mathematical, logical, or textual expressions described in XML and prints the result. The package supports declarations of variables, sub-routines, and XML-based libraries with formulas that can be included in new expression documents. Xmlmath can be used as a stand-alone program from the command-line, but can also be used as a library inside third-party applications. (Source: http://freecode.com/)