Acegi Security is a Java/Java EE framework that provides advanced authentication, authorization and other security features for enterprise applications built using the Spring Framework (Java). This is a powerful, flexible security solution for enterprise software, with a particular emphasis on applications that use Spring. This provides your applications with comprehensive authentication, authorization, instance-based access control, channel security and human user detection capabilities. If you want to read more the please visit these links – Project site, Reference, API docs…
Guice is a lightweight dependency injection framework for Java 5 from the house of google. Guice injects constructors, fields and methods (any methods with any number of arguments, not just setters). Guice includes advanced features such as custom scopes, circular dependencies, static member injection, Spring integration, and AOP Alliance method interception etc. See more on this project page.
Spring’s this version is a bugfix and enhancement release in the Spring 2.0 series, including about 200 (!) refinements and fixes. Furthermore, this release introduces support for the JSR-166 (java.util.concurrent) backport project and basic support for JCA 1.5 (ResourceAdapter bootstrap, WorkManager support), as well as extended support for IBM WebSphere and Oracle OC4J.
Source : here
Technoarti: Spring 2.0