While I was at Drake University, I coauthored (calculus) or revised (linear algebra) two textbooks with Ben Woodruff at Brigham Young University-Idaho. These books are both under the Creative Commons CC-by-sa license.

This book uses an innovative approach to introduce important concepts early in the course and build on those throughout the course.

• Source (on github, using Git to track changes)
• PDF (may be slightly out of date)
• Many homework problems are referenced from Schaum's Outline of Beginning Linear Algebra by Seymour Lipschutz (ISBN10: 0070380376; ISBN13: 978-0070380370)

This is a somewhat rough set of notes presenting multivariable calculus in a comprehensive approach. Highlights include presenting the multivariable derivative as a matrix of partial derivatives and presenting comprehensive physical applications for line, double, surface, and triple integrals using differentials and the concept of weighted averages.

• Source (on github, using Git)
• PDF (may be slightly out of date)