The Jencks project has just released 1.0-M1
Jencks is a lightweight JCA container which is easy to deploy inside Spring to provide Message Driven POJOs as well as to support full inbound and outbound JCA connector support in any Spring application while supporting full XA with recovery (if required).
e.g. here's Message Driven POJOs with Jencks...
Jencks resuses the WorkManager, TransactionManager and BootstrapContext from Geronimo now by default. In case you're worrying about jar-hell - we've a single jar, jencks-all.jar you can add to your classpath and you should have everything you need.
Jencks also includes a number of factory beans and interceptors for working with Geronimo. e.g. we have some helper factory beans for working with Geronimo transaction manager and work manager from Spring...