In a nutshell, pazpar2 is a web-oriented information retrieval client. It will search several (more than 100) targets in parallel and provide on-the-fly normalization and integration of the results. The API can be used it from any development environment. It is particularly easy to use Ajax to build dynamic end-user experiences, and this can be combined with server-side logic to support authentication, resource selection, etc. Configuration can be static, using XML configuration files, or fully dynamic, using the webservice API to configure Pazpar2 on the fly. For examples of interface platforms for Pazpar2, see our Drupal module, our Java ServerFaces module, the Typo3 plugin (not ours), and our most exciting new technology: The MasterKey Widget Set. Pazpar2 is data model-independent -- incoming records are normalized using XSLT to an internal tagged-field representation, and the software can in turn be configured to use different elements of that format for ranking, merging, sorting, facets, and display. Pazpar2 can access information sources directly through SRU, Z39.50, as well as the Apache Solr API.