The Geomajas server is a collection of Java libraries offering GIS utility services aimed at integrating into your existing applications. It has been designed to closely work together with the Geomajas Client, providing extra functionality (such as printing services) and also introducing the "Backend layer" concept.
The "Backend layer" is a GIS layer defined in the Geomajas Server (through XML) which acts like a normal layer (connecting to WMS, WFS, databases, ...) but which can be enriched with extra security rules or business logic. The Geomajas client simply views this as a Geomajas Backend layer and is unaware what manipulations the Geomajas server has done. For example the Hibernate layer plugin can be used to transform any Hibernate POJO object into a GIS layer. This provides endless integration possibilities.
All services in the Geomajas Server make use of pipelines with pre-configured default behaviour through the Spring framework. By customizing this configuration it is possible to tap into any service altering the behaviour to your liking without having to fully overwrite the services themselves.