Rod Johnson in the Interface21 team blog entry named "Oracle Contributing Oracle Application Server Integration Code to Spring Framework" described the contribution of Oracle to Spring framework.
This contribution allows Spring applications to leverage the OracleAS transaction manager and its features. In addition to this contribution and some previous investments of Oracle in Spring, see the Oracle and Spring page of OTN; Oracle continues to invest more and more in Spring, as contributor or as user since, as stated by Rod, Spring has an important roles in Oracle Fusion Middleware, and its upcoming Services Component Architecture offering.