An object-oriented language produced by Bertrand Meyer in 1985. Eiffel has classes with multiple inheritance and repeated inheritance, deferred classes (like Smalltalk's abstract class), and clusters of classes. Objects can have both static types and dynamic types. The dynamic type must be a descendant of the static (declared) type. Dynamic binding resolves multiple inheritance clashes. It has flattened forms of classes, in which all of the inherited features are added at the same level and generic classes parametrised by type.
Other features are persistent objects, garbage collection, exception handling, foreign language interface. Classes may be equipped with assertions (routine preconditions and postconditions, class invariants) implementing the theory of "Design by Contract" and helping produce more reliable software.
Eiffel is compiled to C. It comes with libraries containing several hundred classes: data structures and algorithms (EiffelBase), graphics and user interfaces (EiffelVision) and language analysis (EiffelLex, EiffelParse).
The first release of Eiffel was release 1.4, introduced at the first OOPSLA in October 1986. The language proper was first described in a University of California, Santa Barbara report dated September 1985.
Eiffel is available, with different libraries, from several sources including Interactive Software Engineering, USA (ISE Eiffel version 3.3); Sig Computer GmbH, Germany (Eiffel/S); and Tower, Inc., Austin (Tower Eiffel).
["Eiffel: The Language", Bertrand Meyer, P-H 1992].