An architecture description language is used to specify the structure of a system separately from its algorithmic aspects.

Also known as Module Interconnection Language, Configuration Language.

Examples include:
	* Conic Configuration Language (description at http://www-vs.informatik.uni-ulm.de/DOSinWWW/TextFiles/DPEnvironment/Conic.html)
	* Darwin (http://www-dse.doc.ic.ac.uk/Research/Darwin/)
	* Wright (http://www-2.cs.cmu.edu/~able/wright/)
	* Polylith (papers at http://www.cs.umd.edu/TRs/authors/James_M_Purtilo-no-abs.html)
	* OLAN (French document at http://www.essi.fr/~riveill/recherche/95-olan-francais.html).
	* Acme (http://www-2.cs.cmu.edu/~acme/)

''What is the difference between this and a CompositionLanguage?''

Probably very little, although ADL's are usually declarative, do not have many general programming features and may not be TuringComplete.

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Note UML (http://www.uml.org) is not an ADL but it could be possible to extend some parts of UML to make them an ADL.