Mobile web developers can make use of a new open source toolkit, released this week by Volantis Systems.
The Volantis Mobility Server (formerly called Framework) can now be downloaded under the GNU General Public License version 3. The Java-based software is a framework for building web applications for mobile devices. The applications automatically recast on the fly to adapt specifically to whatever device is accessing the web content.
That means developers, in theory at least, can create a kind of master definition for an application, which is then served up for optimal viewing by different browsers on any of nearly 5,000 current handhelds, according to the vendor.
"Our software takes the master definition in our mark-up language, and compares it with a database of details about the target device, its layout, and its display," says Mark Watson, CEO for Volantis, based on Guildford, England. Mobility Server adapts the mark-up language in response, affecting how the web pages appear and behave on the target device's display. "It exploits the features it knows exist on advanced smartphones, but uses something simpler [and more generic] if those [advanced] features are not available," Watson says.
Volantis is releasing the software to spur the mobile Internet. The idea, says Watson, is that developers can use Mobility Server to make their web applications easily available to a much larger audiences of devices. The company will continue to offer its own applications, built on Mobility Server, and develop new ones. Current applications include: Broker, an online feed manager, and StoreFront, an e-commerce application for selling online content.
In response to a web request from a mobile browser, the Volantis server software queries the device for information, and then combs through, in milliseconds, a database of device details. The database has up to 600 attributes per device, for nearly 5,000 devices. Once it identifies the device, the software can scale images, for example, to best suit the available pixels, or make use of Ajax libraries to validate fields of text or numeric data entered by a user in a form, without having to do so by submitting the form back to the web server.
Volantis developed the toolkit first to support its original products after its founding in 2000. The company focused on supporting television and gaming on web-enabled devices, and its developers needed tools to simplify the problem of optimizing applications for such a diverse group of clients.
The approach tackles the same type of problem as a technique called transcoding, but does more expansively. Transcoding takes one markup language and converts it to another, says Watson. Some approaches made use of the Extensible Stylesheet Language Transformation (XSLT) standard to convert XML documents from one format to another. "XSLT is not a programming language," says Watson. "To do the kind of one-to-many conversions as we do, requires very complex coding, and XSLT is just not up to that."
Rivals include MobileAware, in Dublin Ireland. The company's software was the basis of a web application that lets train passengers buy tickets using any Internet-enabled mobile phone.
Volantis Mobility Server is available at its new community web site. With the GNU GPL, there are no restrictions on use, according to Watson. Besides its applications suite, Volantis will also offer technical support, which includes daily database updates, often number 100 per week. For GPL users, the database will be updated three or four times a year, Watson says.
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