Simeon Simeonov

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Top Stories by Simeon Simeonov

I’ve been around software for 20 years now. Looking back, I have mixed feelings about the progress we’ve made. The end results have been amazing but the process of building software hasn’t fundamentally changed since the 80s. In fact, I see us make some of the same mistakes over and over again. One of the common anti-patterns is over-relying on tools and frameworks instead of inventing new programming models. Layers of abstraction are fundamental to software. Some layers are defined through programming models, e.g., machine language, assembly language, 3GLs, JSP. Others are defined through a combination of tools and frameworks, e.g., MFC and Visual Studio on top of C++. There is a limit to how high we can raise a level of abstraction through tools and frameworks alone. At some point, a new programming model is the best way forward. Here are some examples: CASE tools ... (more)

How Can Metcalfe's Law Be Updated for Web 2.0?

"Metcalfe's Law is Wrong," contended Bob Briscoe, Andrew Odlyzko, and Benjamin Tilly recently in a much-discussed IEEE Spectrum article, in which they wrote: "Of all the popular ideas of the Internet boom, one of the most dangerously influential was Metcalfe's Law." Sim Simeonov disagrees. The industry is at it again – trying to figure out what to make of Metcalfe’s Law. This time it’s IEEE Spectrum with a controversially titled “Metcalfe’s Law is Wrong”. The main thrust of the argument is that the value of a network grows O(nlogn) as opposed t... (more)

The Evolution of XML Protocols

XML protocols can be broadly classified into two generations. First-generation protocols are based purely on XML 1.0. Second-generation protocols take advantage of two revolutionary XML standards - XML Namespaces and XML Schema. This article analyzes the reasons why we need to make a shift to second-generation protocols, and looks at industry activity in this area. First-Generation XML Protocols Generally speaking, protocols specify in detail how certain business/application/network services are accessed through a set of requests and how responses/replies are received. XML protoco... (more)

Web Services Description Language

It's time to look at the details of the Web Services Description Language (WSDL) specification and, in particular, how abstract information about Web services is represented in XML and which extensibility mechanisms enable the binding of abstract specifications to concrete implementations. We start with a quick review of the WSDL information model. In the last XML in Transit (XML-J, Vol. 2, issue 2), we derived an information hierarchy for describing Web services by asking what, how, and where questions. The what question points us to the abstract specification of a Web service.... (more)

A Framework For Using Web Services

In my last XML in Transit column (XML-J, Vol. 2, issue 5) we looked in detail at the technical aspects of the service description layer of the Web Service interoperability stack (see Figure 1). In fact, the topic of our discussion - Web Services Description Language - has now been submitted to the W3C for review. In this column I originally planned to go a step higher and start to map out the space of Web Services advertising and discovery. Instead, I decided to bring the subject of service discovery and advertising within the context of a framework for using Web Services. The ... (more)