The Spring Framework has its origins in the companion code for Rod Johnson’s book, Expert One-on-One J2EE Design and Development (Wrox, 2002). The book developed a strong following of developers, who used the Wrox forums to discuss both the book and the corresponding code. Two of those developers, Juergen Hoeller and Yann Caroff, persuaded Rod to turn the code into an open source project. The book referred to the framework as the Interface21 framework, because Rod felt that it represented the future of enterprise Java development—a framework for the twenty-first century. However, when the open source project was formed, they felt they needed a name that could better inspire a community. Yann suggested Spring because of the association with nature, as well as the fact that Spring represented a fresh start after the “winter” of traditional J2EE development. The project went public in 2003, and version 1.0 of the Spring Framework was released in 2004.