Fundamentals of Programming with C#, Java, JavaScript, Python and C++ Free Books: Official Website

Fundamentals of Computer Programming with C# (English)
Programming Basics with C# Book (English)
Programming Basics with Java Book (English)
Programming Basics with JavaScript Book (English)
Programming Basics with Python Book (English)
Practical Cryptography for Developers Book (English)
Svetlin Nakov's Books Free books about Java, C#, Python, JavaScript, programming and software technologies by Svetlin Nakov
C# Programming Principles (Bulgarian)
Introduction to Programming with Java (Bulgarian)
Programming = ++Algorithms; (Bulgarian)
Programming for .NET Framework (Bulgarian)
Programming Basics with C# Book (Bulgarian)
Programming Basics with Java Book (Bulgarian)
Programming Basics with JavaScript Book (Bulgarian)
Programming Basics with Python Book (Bulgarian)

SoftUni Global Learn Programming and Start a Tech Job
Software University (SoftUni Bulgaria) Courses and trainings on programming and digital skills
SoftUni Kids Programming for children (Bulgarian)
SoftUni Digital Digital marketing academy (Bulgarian)
SoftUni Creative Digital art, design and 3D academy (Bulgarian)
SoftUni Svetlina High School for developers, designers and entrepreneurs (Bulgarian)

Svetlin Nakov's Blog Programming, software engineering and tech education
Bulgarian Association of Software Developers (BASD)
Software University Foundation (Bulgaria) Open courseware content and free trainings for software developers
Applied Software Developer Profession Open learning content from the SoftUni foundation (Bulgarian)
Code with Nakov @ YouTube Free Video Tutorials on Programming and Software Development