Pentaho Data Integration Core documentation

Packages 
Package Description
org.pentaho.di.cluster  
org.pentaho.di.compatibility
Contains all classes that make up the possible Value types: ValueString, ValueNumber, ..., the interface and the Value class itself.
org.pentaho.di.core  
org.pentaho.di.core.config  
org.pentaho.di.core.database
Contains all the different database dialects as well as the DatabaseMeta class (definition) and the Database class (execution)
org.pentaho.di.core.database.map  
org.pentaho.di.core.database.util  
org.pentaho.di.core.date  
org.pentaho.di.core.encryption  
org.pentaho.di.core.exception
This package contains a set of Exceptions used in Kettle.
org.pentaho.di.core.extension  
org.pentaho.di.core.fileinput  
org.pentaho.di.core.gui  
org.pentaho.di.core.hash  
org.pentaho.di.core.jdbc  
org.pentaho.di.core.lifecycle  
org.pentaho.di.core.logging
This package contains the Log4j Kettle appenders and Kettle layout as well as the Kettle Log Message.
org.pentaho.di.core.metrics  
org.pentaho.di.core.namedcluster  
org.pentaho.di.core.namedcluster.model  
org.pentaho.di.core.parameters  
org.pentaho.di.core.plugins  
org.pentaho.di.core.row  
org.pentaho.di.core.row.value  
org.pentaho.di.core.row.value.timestamp  
org.pentaho.di.core.spreadsheet  
org.pentaho.di.core.sql  
org.pentaho.di.core.util  
org.pentaho.di.core.variables  
org.pentaho.di.core.vfs  
org.pentaho.di.core.vfs.configuration  
org.pentaho.di.core.xml  
org.pentaho.di.i18n  
org.pentaho.di.laf  
org.pentaho.di.metastore  
org.pentaho.di.repository  
org.pentaho.di.shared  
org.pentaho.di.version  
org.pentaho.di.www