Content adaptation

Content Adaptation is the action of transforming content to adapt to device capabilities. Content adaptation is usually related to mobile devices that require special handling because of their limited computational power, small screen size and constrained keyboard functionality.
Content adaptation could roughly be divided to two fields: Media content adaptation that adapts media files and browsing content adaptation that adapts Web site to mobile devices.

Browsing Content Adaptation

Advances in the capabilities of small, mobile devices, such as mobile phones (cell phones) and Personal Digital Assistants has led to an explosion in the number of types of device that can now access the Web. Some commentators refer to the Web that can be accessed from mobile devices as the Mobile Web.
The sheer number and variety of Web-enabled devices poses significant challenges for authors of Web sites who want to support access from mobile devices. The W3C Device Independence Working Group described many of the issues in its report Authoring Challenges for Device Independence.
One approach to solving the problem is based around the concept of Content Adaptation. Rather than requiring authors to create pages explicitly for each type of device that might request them, content adaptation transforms an author's materials automatically.
For example, content might be converted from a device-independent markup language, such as XDIME, an implementation of the W3C's DIAL specification, into a form suitable for the device, such as XHTML Basic, C-HTML or WML. Similarly a suitable device-specific CSS style sheet or a set of in-line styles might be generated from abstract style definitions. Likewise a device specific layout might be generated from abstract layout definitions.
Once created, the device-specific materials form the response returned to the device from which the request was made.
Content adaptation requires a processor that performs the selection, modification and generation of materials to form the device-specific result. IBM's Websphere Everyplace Mobile Portal (WEMP), BEA Systems' WebLogic Mobility Server, Morfeo's MyMobileWeb and Apache Cocoon are examples of such processors.
Wurfl and WALL are popular Open Source tools for content adaptation. WURFL is an XML-based Device Description Repository with APIs to access the data in Java and PHP (and other popular programming languages). WALL (Wireless Abstraction Library) lets a developer author mobile pages that look like plain HTML, but converts them to WML, C-HTML and XHTML Mobile Profile depending on the capabilities of the device from which the HTTP request originates.
Alembik (Media Transcoding Server) is a Java (J2EE) application providing transcoding services for variety of clients and for different media types (image, audio, video, etc). It is fully compliant with OMA's Standard Transcoder Interface specification and is distributed under the LGPL open source license.
Launched in 2007, Bytemobile’s Web Fidelity Service was the first carrier-grade, commercial infrastructure solution to provide wireless content adaptation to mobile subscribers on their existing mass-market handsets, with no client download required.