Name:
  Dynamic Linkage

Intent:
  - load a class dynamically (determined at run time)
  - often this class is one of many and was not known
    when the client was coded

Structure:
  - the loadable class must have the same interface
  - client provides some services to loadable classes
  - there is an interface for this called environment

Note:
  - typical plug-in architecture
  - sometimes loadable class are factories