{{language|Eiffel |strength=strong |safety=safe |compat=nominative |checking=static |gc=yes |LCT=yes}}'''Eiffel''' is an [[ISO]]-standardized, [[object-oriented]] programming language designed by Bertrand Meyer and Eiffel Software. The design of the language is closely connected with the Eiffel programming method, a set of principles consisting of [[wp:Design_by_contract|design by contract]], [[wp:Command-query_separation|command query separation]], the [[wp:Uniform_access_principle|uniform access principle]], the [[wp:Single-choice_principle|single-choice principle]], the [[wp:Open-Closed_principle|open-closed principle]], and the [[wp:Option-operand_separation|option-operand separation principle]].

Many concepts initially introduced by Eiffel later found their way into, among others, [[Java]] and [[C#]]. New language design ideas, particularly through the Ecma/ISO standardization process, continue to be incorporated into the Eiffel language.