Here are the classes, structs, unions and interfaces with brief descriptions:

Clutter::Action
Clutter::Actor
Clutter::ActorBox
Clutter::ActorMeta
Clutter::Alpha
Clutter::Animation
Clutter::Animator
Clutter::Backend
Clutter::Behaviour
Clutter::BehaviourDepth
Clutter::BehaviourEllipse
Clutter::BehaviourOpacity
Clutter::BehaviourPath
Clutter::BehaviourRotate
Clutter::BehaviourScale
Clutter::BinLayout
Clutter::Box
Clutter::BoxLayout
Clutter::Cairo::Texture
Clutter::ChildMeta
Clutter::Clone
Clutter::Color
Clutter::Container
Clutter::DeviceManager
Clutter::Effect
Clutter::FixedLayout
Clutter::FlowLayout
Clutter::Geometry
Clutter::Group
Clutter::InitError
Clutter::InputDevice
Clutter::Interval
Clutter::Knot
Clutter::LayoutManager
Clutter::LayoutMeta
Clutter::Media
Clutter::Path
Clutter::Path::Nodes
Clutter::Path::Nodes::const_iterator
Clutter::Path::Nodes::iterator
Clutter::Path::Nodes::reference
Clutter::PathNode
Clutter::Perspective
Clutter::Rectangle
Clutter::Score
Clutter::Script
Clutter::Scriptable
Clutter::Shader
Clutter::Stage	This is a top level 'window' on which child actors are placed and manipulated
Clutter::Text
Clutter::Texture
Clutter::TextureError	Exception class for Clutter::Texture errors
Clutter::Timeline
Clutter::Vertex
Error
Interface
Object