By reading their source code, you can better understand how to use the Spring framework. They are from different areas such as content management systems, online shopping, file management, etc. This article gives you a high-level overview of 20+ open source projects that use the Spring framework. But finally, you still need to read code from real projects. Reading tutorials is a good way for learning at the beginning. Spring framework is difficult to learn, especially when you want to develop a real project with industry standards. In this productive article, I have discussed 20+ free open source projects using the Spring framework for beginners to learn Spring framework in depth.