Two collaboration suggestions: Sage: http://sagemath.org/ http://sagemath.org/ http://math.chapman.edu/~jipsen/tiddly/tiddlymath.html http://math.chapman.edu/

Two collaboration suggestions: Sage: http://sagemath.org/ http://sagemath.org/ http://math.chapman.edu/~jipsen/tiddly/tiddlymath.html http://math.chapman.edu/~jipsen/tiddly/tiddlymath.html (related example: http://deferentialgeometry.org/ http://deferentialgeometry.org/)