Free Calculus books etc.

Bitter

Here! Have a free Calculus book http://www.math.wisc.edu/~keisler/calc.html

Bitter

Oh yes and these too!

http://www.math.gatech.edu/~cain/tex...linebooks.html

Daverz

This one is pretty famous for introducing non-standard calculus using the hyperreal numbers. Apparently there is another approach to this that does not use the hyperreals.