groovy.lang
Interfaces 
AdaptingMetaClass
Buildable
ClosureInvokingMethod
ExpandoMetaClass
GroovyInterceptable
GroovyObject
GroovyResourceLoader
Interceptor
MetaClass
MetaClassRegistry
MetaObjectProtocol
MutableMetaClass
PropertyAccessInterceptor
ProxyMetaClass
Range
Writable
Classes 
BenchmarkInterceptor
Binding
ClassCollector
Closure
ClosureException
DelegatingMetaClass
DeprecationException
DoSetContext
DummyMetaMethod
EmptyRange
ExpandoMetaClassCreationHandle
ExpandoMetaConstructor
ExpandoMetaProperty
GString
GroovyClassLoader
GroovyCodeSource
GroovyLogTestCase
GroovyObjectSupport
GroovyRuntimeException
GroovyShell
GroovySystem
IllegalPropertyAccessException
IncorrectClosureArgumentsException
Index
InnerLoader
IntRange
IntRangeIterator
MOPIter
MetaArrayLengthProperty
MetaBeanProperty
MetaClassCreationHandle
MetaClassImpl
MetaExpandoProperty
MetaMethod
MetaProperty
MethodIndex
MethodIndexAction
MissingClassException
MissingFieldException
MissingMethodException
MissingPropertyException
NonEmptySequence
ObjectRange
ParameterArray
PropertyValue
ReadOnlyPropertyException
Reference
Script
Sequence
SpreadListEvaluatingException
SpreadMap
SpreadMapEvaluatingException
StringWriterIOException
TracingInterceptor
Tuple
WritableClosure