| Introduction to Computer Science using Java | From Central Connecticut State University. It's more about coding than computer science, but not bad. |
| Common Weakness Enumeration | Community-developed list of software vulnerabilities and weaknesses. |
| C Reference Manual | The C Reference Manual by Dennis Ritchie (co-creator of C). |
| The GNU C Reference Manual | The GNU C Reference Manual is a comprehensive reference for GNU C. |
| C Language Reference Manual | The C Language Reference Manual by Silicon Graphics. |
| cppreference | A complete online reference for the C and C++ languages and standard libraries. |
| cprogramming.com | A bit dated, but some good tutorials. Introductory tutorials on several topics including C, C++, graphics, game programming, algorithms & data structures. |
| Programiz: C | A C programming tutorial, good for beginners. |
| Learn-C | A C programming tutorial, good for beginners. |
| tutorialspoint: C | A C programming tutorial, good for beginners, but with a little more depth. |
| cppreference | A complete online reference for the C and C++ languages and standard libraries. |
| cplusplus.com | Another online reference for the C++ language. Articles on C++ programming including UNIX, Windows, etc. |
| MindView | Bruce Eckel's programming website. Includes free downloads of his classic books. Thinking in C++, 2nd ed. Volume 1 Thinking in C++, 2nd ed. Volume 2 |
| Programiz: C++ | A C++ programming tutorial, good for beginners. |
| Learn-C++ | A C++ programming tutorial, good for beginners. |
| Oracle Java Reference version 10 |
Oracle's Java API Reference, Standard Edition & Java Development Kit Version 10. |
| MindView | Bruce Eckel's programming website. Includes free downloads of his classic books. Thinking in Java |
| Programiz: Java | A Java programming tutorial, good for beginners. |
| Learn-Java | A Java programming tutorial, good for beginners. |
| Introduction to Programming Using Java | A free, online textbook on introductory programming using Java. 8th edition. |
| Programiz: Python | A Python programming tutorial, good for beginners. |
| Learn-Python | A Python programming tutorial, good for beginners. |