Apache Camel is an open-source Java framework that focuses on making integration easier and more accessible to developers. It does this by providing:
Concrete implementations of all the widely used EIPs
Connectivity to a great variety of transports and APIs
Easy-to-use Domain-Specific Languages (DSLs) to wire EIPs and transports together
The Integration Manager uses Apache Camel for the configuration of integration flows and it is based on Apache Camel. For the configuration of integration flows is used always Spring XML DLS.
Without a good knowledge of Apache Camel, the usage of Integration manager is not possible.
The recommended page is the Apache Camel project website
A good book about Apache Camel is Camel in action