Getting Spring Security
Spring Security 3.0.3
Spring Security 3.0.3 is the latest production release and the one we would recommed for new development. It requires a minimum of Spring 3.0.3 and Java 5.
Spring Security 2.0.5
The original 2.0 release was at the beginning of 2008 so it is a mature and stable product which is already widely in use. It is compatible with Spring 2.0 and 2.5 releases and requires a minimum of Java 1.4.
Spring Security Snapshot Releases
If you are using Maven as your build system (or another system which can use Maven repositories), then you can build directly against the latest project snapshots by adding the Spring snapshot repository (http://maven.springframework.org/snapshot/) to your build. You can also browse the repository directly.