The possibilities of an XML-based information delivery framework on the desktop

JustSystems has released xfy Technology, possibly the first XML-based information delivery framework on the desktop. David Norfolk looks at what this software is capable of.

Imagine writing an office system today, with no legacy to hold you back. You might build an XML processor which can handle "unstructured" documents (which have lots of structure as long as you can recognise it) as XML documents and translate other structured formats (particularly SQL) into XML for processing. The equivalent of Microsoft Office would just fall out on the way, but you would have a lot more than Office, writes David Norfolk, senior analyst, development, at Bloor Research.

This is more-or-less what JustSystems is offering with xfy Technology, a fundamentally disruptive technology being promoted as "the world's first XML-based information delivery framework". That claim is open to argument - Software AG (for example) has something called Tamino that could take the same description - but it is probably true on the desktop (despite Microsoft's new-found enthusiasm for XML, the OpenXML vs Opendoc disputes suggest that Microsoft might not use XML quite as others do).

JustSystems itself has a respectable provenance, as it claims to be the largest supplier of desktop technology in Japan (it has a suite of Office products), was founded in 1979 and is only now leaving Japan with its xfy product. Interestingly, it acquired XMetaL, an XML-based authoring and content collaboration tool, in 2006.

Xfy is a data processor not a word processor and can create all sorts of standards-based documentation. It could be described as an XML browser, rather than a web browser. It deals with XML from scratch and makes use of XML Schema, Extensible Stylesheet Language Transformations (XSLT) and the extensibility of XML. Ben Walshaw, head of technical services for Emea at JustSystems Europe, says, regarding xfy, that he is fully aware of the semantics issues with XML (XML has no semantics its tags have no "meaning", but we assume meanings when we recognise a tag name), which bodes well for the resilience of xfy-based systems. The semantics issue is important because making assumptions about the meanings of tags can be misleading when you base decisions on them (and such assumptions break down completely when, for example, an English-speaker meets XML written in Korean). The semantics issue is partly addressed by using domain experts to do the tagging (in a medical document, for example, is "black" a name, a colour, a symptom, an emotional metaphor or a colour-coding?) but tagging then becomes a data analysis exercise, with similar political issues and value-add, and it needs a metadata repository to hold the semantic associations.

Xfy is an integrating technology that can present technologies with very different "Look and Feel" in a single rch internet application (RIA) style of interface. To cope with non-internet data sources, it needs to support RIA outside of the browser, which has the useful advantage that disconnected use is supported easily (the last information found is cached and collisions resolved on reconnection). Disconnected use is a bit of an issue with existing RIA applications - such as Silverlight and Flex - but this will probably be addressed, eventually.

Disconnected use brings the problem of several people updating the same information independently and xfy's collision resolution does not seem to be particularly sophisticated for now. However, full versioning/configuration management is supported (nothing is ever overwritten, according to Walshaw, just marked obsolete) so any issues should be resolvable. Strong audit trails are supported.

Xfy competes with Silverlight and Flex, but it is just about XML, not code - it is "just" an RIA-style framework for near-real-time applications. It is most effective in (but not limited to) Java environment, as xfy has a Java-based client that can combine/unify/normalise and visualise information from multiple sources on the client side without the need for server-based scripting. Debuggers are available but everything is built from reusable XML components, so xfy users should not get into deep, complicated programming-style logic.

JustSystems' own internal vision seems to be that "the document is the application". It is reminiscent of IBM's old OS/2 Opendoc vision, although it also seems to be part of the W3C Document Object Model (DOM) vision. Jake Sorofman, vice-president of marketing and business development for North America at JustSystems, says that "JustSystems has the potential to disrupt the document publishing and the application development space. With xfy, the lines blur between these categories. Many processes require the persistence and context of a document and the dynamism and interactivity of a business application. They require structured data to come together with unstructured content - not only on the glass, but as part of a unified document. For many document-centric processes, the document becomes the new application context. We are no longer making a trade off between the live data and interactivity of a business application and the persistence and context of a document".

To summarise, xfy is a new approach to building RIA, which produces composite documents based on standard XML and integration via XSLT. It is a framework for enterprise mashups with role-based visualisation and translation - which "enables" the addition of semantics (meaning) to data (its roadmap seems to support semantic web in the future) and manages complexity. It features fast deployment, and there is no expensive XML parsing before data can be used. It is centralised and server-based.

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