Design Patterns in Object-Oriented Frameworks ( By Savitha Srinivasan IBM）

Framework are particularly important for developing open systems, where both functionality and architecture must be reused across a family of related aplications.

OO framework provide an important enabling technology for reusing both the architecture and the functionality of components.
an OO framework is a set of collaborating object classes that embody and abstract design to provide solutions for a family of related problems. the framework typically consists of a mixture of abstract and concrete classes,  a framework is a semecomplete application that contains certain fixed aspects common to all applications in the problem domain along with certian variable aspects unique to each application generated from it.

the variable aspects called hot spots. while the fixed aspects called frozen spots.

but framework have a steep learning curve since teh user must understand teh abstract design of the underlying framework.

using design patterns to document a framework:
Design patterns are descriptions of communicating objects and classes that are customized to solve a general design problem in a particular context.
two groups: one focuses on OO design and programming or oo modeling. the other ifocuses on patterns that address problems in efficent, reliable , scalable, concurrent, parallel and distributed programming.

Contracts: design patterns descriibe frameworks at a very high level of abstraction. can be introduced as explicit notation to specify the rules that fovern how objects can be combined to achieve certain behaviors.

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