Developer's Guide 
This developer's guide contains information about how you can extend the scope of SAP NetWeaver Enterprise Search using your own developments.
You can develop your own search object connector models and use data provider services to connect other data sources to SAP NetWeaver Enterprise Search. Furthermore, you can use the OpenSearch services to consume the search functions in SAP NetWeaver Enterprise Search in your own applications.
Developing or Extending Search and Analysis Models
If the search and analysis models provided do not meet all your requirements, you can use the modeler delivered with SAP NetWeaver Enterprise Search to develop your own search and analysis models.
More information: Creating or Extending Search and Analysis Models
Developing Applications and Services with OpenSearch Support
You can use the OpenSearch standard, which SAP NetWeaver Enterprise Search supports, to develop your own applications that use the features of SAP NetWeaver Enterprise Search.
More information: Developing Applications That Consume Enterprise Search
Developing Applications and Services That Support Data Provider Services
You can use data provider services (DPS) that SAP NetWeaver Enterprise Search provides to develop your own services that allow you to integrate non-ABAP systems in SAP NetWeaver Enterprise Search and make it possible to search their data.
More information: Developing Services to Integrate Non-ABAP Systems