SAP ERP provides different approaches to integrate Java applications with business logic written in ABAP. With JBoss Fuse, the SOA Platform, and Data Services Platform, Red Hat offers flexible middleware solutions for service-oriented integration and orchestration. As a leading provider of integrated solutions and longtime Premier Partner, akquinet has a long history of projects integrating individual applications based on JBoss with standard ERP software such as SAP or Navision. Based on various real world examples, we will show different ways to integrate SAP ABAP backends with JBoss Middleware. We will discuss the pros and cons of integrating Java EE applications using (a) the REST based approach with NetWeaver Gateway, (b) JBoss Data Services Platform with NetWeaver Gateway (c) SOAP based Web Services and (d) Remote Function Calls with the Java EE Connector Architecture (JCA) and the SAP Java Connector (JCo) library