ODE Textbook:

Introduction to Differential Equations. This is a free, open-source, online textbook that covers the second ~2/3 of Math 204.

The original book was authored by J. Lebl and was significantly adapted for Math 204, with most notable of the changes being the inclusion of a video playlist throughout the textbook.

The source code can be found at my github. This work is supported by an Open Education Resources  (OER) grant through LTSI at Uvic.

Vector Calculus “book”:

Introduction to Vector Calculus. This “book” is primarily a video series on vector calculus covering the first ~1/3 of Math 204, but the videos are scaffolded by surround text introductions, learning objectives, pre- and post-video activities, and other resources.