Constraint Interchange Format (CIF)
The Constraint Interchange Format (CIF) is under development as part of the AKT project, aimed specifically at business-to-business e-commerce applications on the Semantic Web. It has been used successfully in diverse and challenging application domains such as representing and reasoning about protein structures in biomedical applications  and configuring telecommunications network services . Earlier versions of the CIF were based on Prolog term structures; there is also a new XML encoding of the CIF, designed to be more open and less platformdependent than its predecessor. The XML-CIF  has been modelled using the XML Schema specification, so that constraints become Web resources about which statements can be made (for example, statements about the authorship and context of a constraint). In addition, the CIF has been designed to refer to XML Schema definitions so that the terms referred to in a constraint can have corresponding XML Schema descriptions. The motivation here is to allow, in principle, any application of RDF Schema to use CIF and constraint-solving services.
 P. Gray, K. Hui, and A. Preece. An Expressive Constraint Language for Semantic Web Applications. In IJUAI01 Workshop on E-Business 4 the Intelligent Web, pages 46-53, 2001. PDF
 Kemp, G.; Robertson, C.; Gray, P.; and Angelopoulos, N. CORBA and XML: Design Choices for Database Federations. In Lings, B., and Jeffery, K., eds., Advances in Databases: Proc. BNCOD17 Conference, 191–208. Springer-Verlag(LNCS1832). 2000.
 Fiddian, N. J.; Marti, P.; Pazzaglia, J.-C.; Hui, K.; Preece, A.; Jones, D. M.; and Cui, Z. 1999. A knowledge Processing System for Data Service Network Design. In BT Technical Journal 17(4):117–130.