Gilbert Strang. RES.18-001 Calculus Online Textbook. Spring 2005. Massachusetts Institute of Technology: MIT OpenCourseWare, https://ocw.mit.edu.
License: Creative Commons BY-NC-SA.
Published in 1991 by Wellesley-Cambridge Press. In addition to the Textbook, there is also an online Instructor's Manual and a student Study Guide. Prof. Strang has also developed a related series of videos, Highlights of Calculus, on the basic ideas of calculus.
The 2010 second edition of the Calculus textbook includes a new chapter on "Highlights of Calculus" that connects to the video series of the same name. The new chapter has summaries and practice questions for all of the videos. It also introduces The Exponential Function (e^x) as presented in Prof. Strang's video on this topic.
Calculus on the Web (COW) is an internet utility for learning and practicing calculus. The principal purpose of COW is to provide you, the student or interested user, with the opportunity to learn and practice problems in calculus (and in the future other topics in mathematics) in a friendly environment via the internet. The most important feature of the COW is that you get to know whether your answer is correct almost immediately. It is as if you had a tutor looking over your shoulder and helping you along as you work. This will be true no matter where you are or what computer you use, as long as it is connected to the internet and has a web browser. Attribution information