Developing Virtual Synthesizers with VCV Rack guides the reader through the process of creating synthesizer modules using the intuitive VCV Rack and its open-source C++ API. Ideal for both beginners and experienced users, this book covers oscillators, filters, and complex modules, progressing from basic concepts to more advanced examples. Practical topics such as plugin release management and graphical user interaction are explored, alongside a tailored study of signal processing theory specific to sound synthesis and virtual analog techniques. Each chapter includes exercises and example patches to help build a comprehensive library of synthesizer modules that can be customized and expanded upon. This resource is perfect for undergraduate and postgraduate students in audio engineering, music technology, computer science, electronics, and related fields; DIY enthusiasts; and professionals seeking a detailed guide to VCV Rack. VCV Rack, the free and open-source software discussed in this book, is available online.