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Device Independence and the Web
Gimson, Roger
HPL-2002-249
External - Copyright Consideration
Keyword(s): No keywords available.
Abstract: The Web is steadily increasing its reach beyond the desktop to devices ranging from mobile phones to domestic appliances. This rapidly expanding accessibility is largely due to the Web's foundation in open protocols and markup languages, which offer the most widely implemented global infrastructure for content and application access. HTML's original aim was to provide a device-independent markup language that was based on document semantics. It identified document elements such as headings, paragraphs, and lists without specifying presentation. Early on, however, browser developers introduced many ad hoc presentation-specific elements and attributes to HTML that blurred the distinction between semantics and presentation. A presentation created for a large- screen device, for example, can theoretically be displayed and interacted with on a small-screen device because they use the same markup. Practically, however, it might be too hard to use simply because the author did not create the presentation with a small form-factor in mind. Device independence is an attempt to regain some of Web publications' original intent. Web standards are now encouraging a renewed distinction between semantics and presentation through styling languages such as Cascading Style Sheets (CSS) and Extensible Stylesheet Language Formatting Objects (XSL-FO) for adding information to Web output, and interaction markup languages such as XML Forms (XForms) for input. As the number of devices accessing the Internet increases, the problem of creating presentations for each device type grows worse. Ideally, authors would need to create only one version of their Web content. Then, during the delivery and rendering process, adaptation software would create a presentation to match the delivery device's capabilities.
10 Pages
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