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Extensible Mark-up Language, a way of
describing and sharing data on networks. Like its cousin html, xml
consists of a set of tags that describe a chunk of data. The
resemblance more or less ends there. Xml is designed to describe the
content of a page in terms of the type of data it contains, rather
than the way that data should look. So while an html tag such as <font>
simply specifies that the following text should be display in a particular
size and weight, an xml <fish> tag might indicate that the following
data describes a perticular species of fish.
This characteristic of
xml makes it easy for like-minded groups of people to share
information, because they need only agree on a set of tags that meets their
particular needs. Thus a global consortium of fishmongers might agree on a
standard way of describing information about fish catches - the number
landed, the average size of the fish, the different species - and use their
own xml tags to actually store the data. An intelligent search
engine could then look for data types rather just words: all the
fishmongers who landed haddock of a particular size on a specified date,
rather than just any website containing the word haddock.
After a slow start, xml is now in widespread use.
Microsoft's Channel Definition Format, for example, which describes how
broadcast-like data channels should be interpreted by browsers, is
based on xml, and the language is being used to format everything
from news feeds to search-engine results. All sorts of variants are
appearing that are being used to solve a wide variety of problems: aixml
to create intelligent web bots, for example, and Voicexml
to create voice-enabled applications such as voice portals and
recognition system. But the language's real importance in the future is in
business-to business e-commerce, where its ability to help companies
share information will make the automation of many business processes much
easier. Many of the web';s most interesting developments such as web
services are based on xml, and it is establishing itself in
businesses and other organisations as they become ever keener to maximise
the efficiency of their online operations. |
