GeoGebra–Free and open source software for learning and teaching mathematics. (See http://GeoGebra.org and http://GeoGebraCA.org for more information)

LibreOffice (for Windows) (for Mac)–LibreOffice is the power-packed free, libre and open source personal productivity suite for Windows, Macintosh and GNU/Linux, that gives you six feature-rich applications for all your document production and data processing needs: Writer, Calc, Impress, Draw, Math and Base.