The Spring Framework is an open source application framework for the Java platform and .NET Framework (Spring.NET). The first version was written by Rod Johnson who released the framework with the publication of his book Expert One-on-One J2EE Design and Development in October 2002. The framework was first released under the Apache 2.0 license in June 2003. The first milestone release, 1.0, was released in March 2004, with further milestone releases in September 2004 and March 2005. The Spring 1.2.6 framework won a Jolt productivity award and a JAX Innovation Award in 2006. The current version is 3.0. The core features of the Spring Framework can be used by any Java application, but there are extensions for building web applications on top of the Java Enterprise platform. Although the Spring Framework does not impose any specific programming model, it has become popular in the Java community as an alternative to, replacement for, or even addition to the Enterprise JavaBean (EJB) model. SpringSource was purchased for $420m by VMware in August 2009.