Smalltalk

Smalltalk was developed at the beginning of the 70's in the research laboratory of Xerox and should be - also by the comfortable integration into the interactive graphic development environment - a programming language for the simple modeling of non-numeric problem areas. Its development had a strong influence not only on most object-oriented language developments, but also on the design of graphical user interfaces - e.g. Macintosh, Motif.

Smalltalk does not support static typing. All features are inherited. Methods can be redefined in the process. Multiple inheritance, on the other hand, is not possible. Furthermore Smalltalk supports polymorphism. There is "late binding" without restriction to subclass instances. In the absence of typing, there is no overloading.

For each class there is a metaclass. There typically the creation and initialization methods as well as the characteristics of the class objects are defined. All methods are externally visible, attributes however only in the definitions of the subclasses. Generic or also parameterizable classes are not supported.

Objects are created explicitly by calling "new". The constructor defined in the class is called for initialization "initialize". The garbage collection can be switched on/off explicitly.

Concurrency of method executions is possible. The comfortable integration into the graphical development system allows fast prototyping. By so-called inspectors objects can be supervised for error tracing. Smalltalk gets along almost without keywords.