Spec is a framework in Pharo for describing user interfaces.

Spec is included in any regular Pharo image.
It is possible to load the latest version executing following script:

 Metacello new repository: 'github://pharo-spec/Spec'; baseline: 'Spec2'; onConflict: [ :e | e useIncoming ]; onUpgrade: [ :e | e useIncoming ]; ignoreImage; load