Improvements to the open-source Spring Java framework and a companion Web technology being unveiled Monday focus on annotations, scripting, and Java (Java Platform Standard Edition) 6, developers of the framework said.

Officials of Interface21, which oversees development of Spring technologies, will reveal plans for Spring Framework 2.1 and Spring Web Flow 1.1. Both will be available in a release candidate form at the JavaOne conference, which begins in San Francisco on May 8. Final releases are planned for June.

Having been downloaded 3 million times, Spring has become popular for Java application development because it combines simplicity and power and can be used in mission-critical applications, said Rod Johnson, founder of Spring and CEO of Interface21.