This resembles viewing microfiche films, i.e., pictures of data, not the data itself. In order to be extracted, data should be presented in a predefined format. Such a presentation seriously limits its usefulness. Regrettably, these HTML collections are generally unprocessable, i.e., there is no way to provide universal software for extracting data from HTML pages. The tools to build, test, and deploy business web sites are in short supply.
Many developers focus more on building attractive rather than useful sites.
By providing a means of separating actual data from the presentation of that data, XML offers an indispensable common foundation for extraction of data from heterogeneous structured data sources. XML allows documents to be obtainable and viewable in a contextually aggregated form. However, XML by itself is not enough for enabling coherent and semantic data viewing. An appropriate XML-enabled software technology is required for this challenge. In particular, such software should do the following.