As WebSphere Application Server (especially 6.x) onwards, it supports JPA (Java Persistence APIs). Its default ORM tool is OpenJPA. It also supports easy plugging with other ORM tools. For distributed caching, WAS (WebSphere? Application Server) uses DynaCache for distributed caching and very useful in clustered environment. As it has pluggable caching architecture so any ORM tool can easily gets plugged with the ORM caching adapter.
As Hibernate is very famous and stable ORM tool. But it has an issues with WAS as it doesn't have a Hibernate caching adapter to plug with IBM's distributed caching framework.
So I decided to make WebSphere-Hibernate DynaCache adapter so that anyone can easily use the renowned Hibernate ORM.
Please visit my project at http://code.google.com/p/webspherehibernateadapter/ for more detail.