WSDL - Web Services Description Language

WSDL 1.1 was originally developed by Microsoft and IBM in 1999, and was proposed to the W3C.

Since then the W3C has been working on developing drafts of the next version of WSDL, which was originally known as WSDL 1.2 but then renamed to be WSDL 2.0.

WSDL is based on the XML Schema technology.

XML Schema Technology is currently in version 1.0, released in 2001.

XML Schemas define the semantics of messaging for XML services. An XML Schema is used as a central point to coordinate the messaging. Note that WSDL does not have to use XML Schemas, so long as users of WSDL are happy with a common semantics

There are two forms of semantics:

Type 1 - data elements with structure - this is what is usually found in XML Schemas

Type 2 - the scenarios in which data elements can be used, where these can be stored is a moot point traditionally, business procedures of companies are secret and copyright of corporations.

Best practices have been promoted by industry bodies, consulting companies and software companies like SAP, Baan, Oracle and Peoplesoft and JD Edwards.

The WSDL language is designed to work with SOAP.

One of the major questions is what will persuade companies to agree to over to WSDL compliant processing, when other initiatives in the past have foundered necuase organisations just cannot afford to make all the data changes. Typically, budgetary decisions are made to migrate to applications that hold data in "proprietary" formats, as there is no inertia behind non-proprietary formats.

It is possible that the inertia of WS-I Web Services Interoperability and W3C will be enough to begin to make companies consider the possible benefits of incorporating the changes into the .

The industry has a collective interest in motivating companies to make that leap to make their systems compliant.

This however does not address the issue of security and there is a real risk that the whole enterprise will founder on concerns of security. Would you open up your systems to a standard that would allow unknown systens to come and query your database? Without some careful scrutiny, the answer is probably no.

Historically, if we look at secure systems, the only mechanism of securing systems, is to make ure there are no connections between your site and the outside world. This is something that is appropriate for government level organisations. This includes the use of wireless technologies.

One possibly solution is to zone the data, so that data of varying levels of security can be accessed by varying levels of internet programs.

In this case, a model for security deployment is required.

Also we need to look at the extent to which web services will be a disruptive technology. Disruptive technology is a codeword which means that when it is released someone in business is going to lose a lot of money.

IBM Microsoft SAP Peoplesoft Oracle Financials

W3C

SOAP