* [3D Programming in Java](http://www.mat.uniroma2.it/~picard/SMC/didattica/materiali_did/Java/Java_3D/Java_3D_Programming.pdf) - Daniel Selman (PDF)
* [Apache Jakarta Commons: Reusable Java Components](http://ptgmedia.pearsoncmg.com/images/0131478303/downloads/Iverson_book.pdf) - Will Iverson (PDF)
* [Artificial Intelligence - Foundation of Computational Agents (2010)](http://artint.info/html/ArtInt.html) - David Poole and Alan Mackworth
* [Artificial Intelligence - Foundations of Computational Agents, Second Edition](https://artint.info/2e/html/ArtInt2e.html) - David L. Poole and Alan K. Mackworth
* [Category wise tutorials - J2EE](https://www.mkyong.com/all-tutorials-on-mkyong-com/) - Yong Mook Kim
* [Core Servlets and JavaServer Pages, 2nd Ed. (2003)](http://pdf.coreservlets.com) - Marty Hall and Larry Brown
* [Data Structures in Java for the Principled Programmer (2007)](http://dept.cs.williams.edu/~bailey/JavaStructures/Book_files/JavaStructures.pdf) - Duane A. Bailey (PDF)
* [Data Structures in Java for the Principled Programmer (2007)](https://web.archive.org/web/20190302130416/http://dept.cs.williams.edu/~bailey/JavaStructures/Book_files/JavaStructures.pdf) - Duane A. Bailey (PDF)
* [Java Notes for Professionals](http://books.goalkicker.com/JavaBook/) - Compiled from StackOverflow documentation (3.x)
* [Java Programming for Kids](https://yfain.github.io/Java4Kids/) - Yakov Fain
* [Java Projects, Second Edition](https://www.packtpub.com/free-ebooks/java-projects-second-edition) - Peter Verhas (Packt account *required*)
* [Java: The Legend](https://www.oreilly.com/programming/free/java-the-legend.csp) - Ben Evans (email address *requested*, not required)
* [Learning Java (4th Edition)](http://chimera.labs.oreilly.com/books/1234000001805/index.html) - Patrick Niemeyer and Daniel Leuck
* [Microservices Best Practices for Java](https://www.redbooks.ibm.com/redbooks/pdfs/sg248357.pdf) (PDF)
* [Microservices for Java Developers](http://www.oreilly.com/programming/free/microservices-for-java-developers.csp) - Christian Posta (email address *requested*, not required)
* [Modern Java EE Design Patterns](http://www.oreilly.com/programming/free/modern-java-ee-design-patterns.csp) - Markus Eisele (email address *requested*, not required)
* [Neural Network Development with Java](https://www.packtpub.com/packt/free-ebook/neural-networks-java) - Alan M. F. Souza and Fabio M. Soares (email address *requested*, not required)
* [Object-Oriented Programming in JavaTM Textbook](http://computing.southern.edu/halterman/OOPJ/) - Rick Halterman (PDF per Chapter)
* [Object Oriented Programming using Java](https://bookboon.com/en/object-oriented-programming-using-java-ebook) - Simon Kendal (PDF) , Bookboon. (email address *requested*, not required)