Jakarta Connectors (JCA; formerly known as Java EE Connector Architecture and J2EE Connector Architecture) are a set of Java programming language tools designed for connecting application servers and enterprise information systems (EIS) as a part of enterprise application integration (EAI).
The Jakarta Connector Architecture defines a standard for connecting a compliant application server to an EIS.
It defines a standard set of system-level contracts between the Jakarta EE application server and a resource adapter.
Siebel provides API to integrate with various platforms like Java, C++, .NET, Visual Basic, etc.
Great Plains Systems provides an interface called eConnect to integrate with other platforms.