Introduction Information gateways, in common with other Internet-based services, need to make important decisions about the use of standards. Standards can be utilised for many of the functions that an information gateway typically offers. For the purpose of this chapter's overview, the term standard refers to all three. Standards define the interfaces between components in systems and the data-structures that pass across those interfaces. By building or using systems that conform to open standards we allow components that have been developed by others to interface with ours.
Standards are the mechanism of co-operative development.
The use of systems that are not standards-based normally leads to proprietary, single vendor solutions. Because information gateways are complex, co-operative systems, using standards makes sense. However some of the standards relating to interoperability are the subject of ongoing research . One area where this is particularly true is with index sharing among servers in order to provide the 'forward knowledge' required for query routing . Another is the ordering and ranking of results from multiple search targets.