Drupal now has many tools for rapidly and efficiently bringing large amounts of external data into Drupal, and visualizing different specific combinations of the data - "data mashups" - with Views and other Drupal UI tools.
For example:
Feeds and feed-related tools, such as PubSubHubBub can be used to bring RSS, Atom, CSV, etc. data into Drupal.
The Data module can be used to store external data into custom Drupal databases that allow that data to be processed and visualized using various hooks for Views.
The Services module can be used to create data mashups using external data via web services, which can work through various interfaces, including XML-RPC, AMFPHP, JSON, REST, SOAP, etc.
Solr and Sphinx can now be combined to effectively index large amounts of data either external or internal to Drupal, which can then be viewed and/or stored in Drupal
QueryPath and other XPath or XSLT-based tools can be used to process large amounts of external or internal XML or XHTML data in Drupal.
Specific examples of using Data Mashups with Drupal for creating custom Knowledge Bases for academic or personal research will be presented as use cases.
Intermediate Drupal developers are the main target, but beginners and experienced developers will also find some useful information and benefit.
Also, non-devs such as themers, site admins and information architects can benefit from seeing what is possible now for creating Data Mashups with Drupal.