Calculus

This is a calculus textbook at the college Freshman level based on Abraham Robinson's infinitesimals, which date from 1960.  The First Edition of this book was published in 1976, and a revised Second Edition was published in 1986, both by Prindle, Weber & Schmidt. The book is now out of print and the author decided (as of September 2002) to make the book available for free in electronic form at this site.