Work on outline 1. Introduction 2. ContextJS 2.1. Defining Layers 2.1.1. Refine Existing Methods 2.1.2. Override Methods 2.2. Scoping Layers 2.2.1. Global 2.2.2. Dynamic 2.2.3. Object Specific 3. Webwerkstatt To put the absolut numbers of the COP usage in relation, we give an overview of the size of werbwerkstatt. 3.1. Loading a Lively Kernel World 3.2. Repository: Core, Apps, Project, Users 3.3. PartsBin 3.4. Worlds 4. Sources of Layer Defitions and Activations 4.1. In Core and Apps 4.2. In Lively Projects 4.3. In Parts 4.4. In Worlds 4.4.1. Scripts in Objects 4.4.2. Text and Workspaces 4.4.3. Object specific Layer Activation 4.5. Example Runtimes 4.5.1. Analysing Meta-objects at runtime 4.5.2. Analysing objects at runtime 4.5.3. Tracing Execution 5. Layer Definitions 5.1. Most common layered, classes and Methods 5.2. Proceed and Overriden Methods 5.2.1. Histogram for Proceed 5.2.2. Histogram for Overriden 5.2.3. Occurrence of Class and Method in Layers 5.2.4. How often methods 5.2.5. Unknown Layers in Worlds 6. Layer Activations Counting Layer Activations at in code 6.1. Tracing Layer Activations 6.2. Tracing Layer Activations How often do layer (de-)activations actually happen at runtime? 7. Alternatives to COP in Lively 7.1. Method Wrappers 7.2. Connectors 7.3. Hooks 7.4. Traits 7.5. Instance Specific Behavior 7.6. Conditionals 7.7. Delegation