| Abstract Factory | Provide an interface for creating families of related or dependent objects without specifying their concrete classes |
| Adapter | Convert the interface of a class into another interface clients expect. Adapter lets classes work together that couldn’t otherwise because of incompatible interfaces |
| Bridge | Decouple an abstraction from its implementation so that the 2 can vary independently. |
| Builder | Separate the construction of a complex object from its representation so that the same construction process can create different representations. |
| Chain of responsibility | Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it. |
| Command | Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations. |
| Composite | Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. |
| Decorator | Attach additional responsibilities to an object dynamically. Decorations provide a flexible alternative to subclassing for extending functionality. |
| Facade | Provide a unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use. |
| Factory method | Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory method lets a class defer instantiation to subclasses. |
| Flyweight | Use sharing to support large numbers of fine-grained objects efficiently. |
| Interpreter | Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language. |
| Iterator | Provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation. |
| Mediator | Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently. |
| Memento | Without violating encapsulation, capture and externalize an object’s internal state so that the object can be restored to this later. |
| Observer | Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. |
| Proxy | Provide a surrogate or placeholder for another object to control access to it. |
| Singleton | Ensure a class only has one instance and provide a global point of access to it. |
| State | Allow an object to alter its behaviour when its internal state changes. The object will appear to change its class. |
| Template method | Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template method lets subclasses redefine certain steps of an algorithm without changing the algorithm’s sturcture. |
| Visitor | Represent an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which it operates. |