A mathematical expression parser VCL component that can be used with Borland Delphi 4, 5, 6, 7 and Borland C++ Builder 3, 4, 5, 6. Source code might work with Kylix as well. [Commercial]
This site has components for Delphi, C++ Builder, COM, ActiveX, and NetObjects Fusion. Component categories include Mathematical Expression Parsers, ISAPI/CGI, NetObjects Fusion Extensions.