Download Spring from http://www.springframework.org/download. Select the -with-dependencies.zip to get also all required plugins. At this time of writing I downloaded the version Spring Framework 2.5.5.

The folder "dist" contain the Spring container "spring.jar". The folder lib contains additional require libraries. A minimal Spring application requires the spring.jar, commons-logging.jar (from \lib\jakarta-commons) and log4j*.jar (from \lib\log4j).