*The Ordinary Differential Equations Project*—A Work in Progress

*The Ordinary Differential Equation Project* is an open source textbook designed to teach ordinary differential equations to undergraduates. This is a work in progress by Thomas W. Judson. The books strengths will include a wide range of exercises, both computational and theoretical, plus many nontrivial applications. Technology is integrated into the textbook using the open source system, Sage.

This textbook is licensed with a GNU Free Documentation License (GFDL). There is no cost to acquire this text, and you are under no obligation whatsoever to compensate or donate to the authors or publisher—for all intents and purposed *The Ordinary Differential Equation Project* is a free textbook. You make as many copies as you like, ensuring that the book will never go out-of-print. You may modify copies of the book for your own use—for example, you may wish to change to a prefered notation for certain objects or add a few new sections. There is a copyright on the book, and subsequently it is licensed with a GNU Free Documentation License (GFDL), allowing the author to give you greater freedoms in how you use the text. The main caveat is that if you make modifications and then distribute a modified version, you are required to again apply the GFDL license to the result so that others may benefit from your modifications.

Although the *The Ordinary Differential Equations Project* is still in development, the book is now being used at several universities. For this reason, I have decided to begin declaring annual editions each fall with a snapshot editions whenever appropriate.

- Full Text, Snapshot (HTML, September 7, 2021)
- Full Text, Snapshot (PDF, 25.2 MB, September 7, 2021)
- Full Text, 2021 edition (HTML, August 21, 2021)
- Full Text, 2021 edition (PDF, 25.2 MB, August 21, 2021)
- Full Text, 2020 edition (HTML, August 1, 2020)
- Full Text, 2020 edition (PDF, 25.2 MB, August 1, 2020)
- Full Text, 2019 edition (HTML, August 21, 2019)
- Full Text, 2019 edition (PDF, 25.2 MB, August 21, 2019)
- Full Text, 2018 edition (HTML, August 19, 2018)
- Full Text, 2018 edition (PDF, 24.2 MB, August 19, 2018)

## Other Open Source Textbooks, Software, and Resources

- Open Textbook Initiative. The The American Institute of Mathematics (AIM) has developed evaluation criteria to identify the open source textbooks that are suitable for use in traditional university courses. The Editorial Board maintains a list of approved textbooks which have been judged to meet these criteria.
- UTMOST: Undergraduate Teaching in Mathematics with Open Software and Textbooks. The UTMOST project was an NSF CCLI Type 2 grant to promote open source software and curriculum materials in the undergraduate mathematics classroom.
- MathBook XML is a lightweight XML application for authors of scientific articles, textbooks and monographs that incorporates the best of DocBook, LaTeX, and HTML. When a document is written in MathBook XML, it is possible to quickly produce print, PDF, web, EPUB, Sage Notebooks, and iPython Notebooks from a single source.
*Abstract Algebra: Theory and Applications*, an open source textbook by T. W. Judson available in PDF format, hardback, and online*A First Course in linear Algebra*, an open source textbook by R. Beezer.*Sage*, open source mathematics software founded by W. Stein.*The SageMathCloud*, a collaborative environment for doing mathematics by W. Stein.