The iMath extension to Openoffice.org enables numeric and symbolic calculations inside a Writer document. iMath makes use of the EQC library ( EQC homepage).
The development of iMath was prompted by a problem which I often encountered doing calculations in my profession as a mechanical engineer. I would first begin writing out the problem on paper, putting together the necessary equations, and then turn to a spreadsheet to do the actual calculations. EQC is meant to integrate this process in a single OOo text document.
Programming language: C++, bison, flex. Implemented on Linux-i386. Cross-compiled to Windows, but not extensively tested there.
iMath makes use of the EQC library for numeric and symbolic calculations.
All code changes are documented in the source files by three asterixes (***) and the change number.