Concise Notes on Data Structures and Algorithms: Ruby Edition is a text for a standard foundational course in the topic. It emphasizes abstract data types and covers standard containers, algorithm analysis, sorting and searching, hashing, binary search trees, and graphs. Ruby is used for code examples and exercises, but not taught in the book. Code for the book is available on the web. The text presents its topics in short, readable chapters that still provide pedagogical support in the form of examples, review question and answers, exercises, and a glossary.