.Math Expression Compiler

Welcome to .Math, the OpenSource expression compiler for the .NET platform written entirely in C#. Offering speed through compilation of expressions, the library allows for variable handling, an entire function library and the ability to add your own functions.

[via Green Dragon's Lair » Blog Archive » .Math expression compiler]

Info here, GotDotNet Workspace (with 1.0 Release) here. Play with the demo web page here - a random sample formula to get you started is 1/sin(exp(x)) + cosh(x).