CompPad is an open-source alternative to MathCad, implemented as an extension to OpenOffice.org Writer.
Eperimental Release 3, based on Subversion Rev. 43, demonstrates a framework for handling units of measure, vectors, matrices, and complex numbers, although this implementation is still incomplete.
This experimental release is implemented as an OpenOffice.org extension. In OpenOffice.org version 3, installation should be as simple as opening the file CompPad_r43.oxt using the File->Open... menu, or else the extension manager under Tools->Extension Manager... menu. OpenOffice.org will then prompt you to install the extension.
The extension adds a "CompPad" menu to the menu bar. Use the menu item "CompPad->Evaluate Expressions" to evaluate the mathematical expressions in the document.
Two example documents are included in the release:
CompPadDemo_r43.odt - This file contains examples of all the operators so far implemented.
example-fluid_mechanics_r43.odt - This file is an example of an engineering calculation using CompPad.