Last updated at 8:47 pm UTC on 9 December 2017
Citation from page 8 of the Spec booklet
Spec is a standard UI framework in Pharo and differs from the other UI frameworks present: Morphic and the GT Tools.
Morphic is a general-purpose graphics system originally built for the Self language, and later included in Squeak (the ancestor of Pharo). Morphic provides standard UI widgets, and as such is used by Spec to render UIís, but can also be used to build any kind of graphical shape and allows for their direct manipulation.
Spec is more restricted than Morphic in that it only allows one to build user interfaces for applications that have typical GUI widgets such as buttons, lists et cetera.
The GT tools are more restrictive than Spec since they target the domain of development tools. The GT Tools therefore restrict and simplify UI construction to layouts and workflows typical to development environments.
Spec does not have these restrictions, which can make UI construction more intricate but allows for a wider variety of UIs.
Important methods to construct a UI are