weka.clusterers
Interfaces 
NumberOfClustersRequestable
UpdateableClusterer
Classes 
CheckClusterer
Clusterer
ClusterEvaluation
Cobweb
DBScan
DensityBasedClusterer
EM
FarthestFirst
FilteredClusterer
MakeDensityBasedClusterer
OPTICS
RandomizableClusterer
RandomizableDensityBasedClusterer
RandomizableSingleClustererEnhancer
SimpleKMeans
SingleClustererEnhancer
XMeans