We’re happy to announce the release of a free and open textbook, An Introductory Course in Elementary Number Theory, by Dr. Wissam Raji, Ph.D., of the American University in Beirut. Fuller details are here, and be sure to check out our Q&A with the author.

Dr. Raji created this text in response to a need for a clear, concise book oriented toward those just getting started in number theory. His work was selected by the Saylor Foundation’s Open Textbook Challenge for public release under a Creative Commons Attribution (CC BY) license.

The book is available in a clean, readable PDF, in .doc and EPUB, and in its native TeX for those who wish to re-mix the work for use in their classrooms. You can explore this and other titles at our bookshelf.