org.eclipse.core.commands
Interfaces 
ICategoryListener
ICommandListener
ICommandManagerListener
IExecutionListener
IExecutionListenerWithChecks
IHandler
IHandlerAttributes
IHandlerListener
INamedHandleStateIds
IObjectWithState
IParameter
IParameterTypeListener
IParameterValues
IStateListener
ITypedParameter
Classes 
AbstractHandler
AbstractHandlerWithState
AbstractParameterValueConverter
Category
CategoryEvent
Command
CommandEvent
CommandManager
CommandManagerEvent
ExecutionEvent
HandlerEvent
Parameterization
ParameterizedCommand
ParameterType
ParameterTypeEvent
State
Exceptions 
ExecutionException
NotEnabledException
NotHandledException
ParameterValueConversionException
ParameterValuesException
SerializationException