Composition Languages for Black-Box Components
Even though at the moment several component systems exist on top of object-oriented programming languages, we feel that there is need for pure component languages. These languages are needed to provide a component developer with a clean and concise vocabulary and semantics for building and composing components. We feel that, just as object oriented programming languages gave rise to the notion of íreuse of designí, better component languages will answer new problems (and raise new questions).
Piccola has been mentioned on LtU.
Soul allows declarative reasoning about object-oriented (Smalltalk) programs.
I should have known there would be a Scheme based language, Unit d - Units: Cool Modules for HOT Languages