In [[computer programming]], a '''Traittrait''' is an [[abstract type]], used as a "simple conceptual model for structuring [[object oriented]] programs."[http://web.cecs.pdx.edu/~black/publications/TR_CSE_02-012.pdf]. Traits are similar to [[mixin]]s, but may include definitions for class methods. Traits have been proposed for inclusion in [[Smalltalk]], [[ActionScript|ActionScript 3.0]] and [[PHP]], and are found in Moose ([[Perl]] 5), [[Perl 6]], and [[Scala programming language|Scala]]. ''Module mixins'' in [[Ruby (programming language)|Ruby]] are similar to traits to some degree.
Traits were initially developed at the Software Composition Group, [[University of Berne]].
