Without having to ask me, the LibreTexts project has adopted Applied Discrete Structures (ADS) to their library! Don't get me wrong - the point to making ADS an OER project is to make it available to as many instructors and students as possible at no cost. So I'm delighted that they've added the project.
I was unfamiliar with LibreTexts until now. Understandable because its a relatively new project. It started with Chemistry content but has since branched in to other sciences, mathematics, engineering and more.
For a good introduction to LibreTexts check out this video from LibreFest 2023
Applied Discrete Structures is still available in other form factors at https://discretemath.org