Pazpar2 uses Z39.50 as its switchboard language -- i.e. as far as it is concerned, all resources speak Z39.50, its webservices derivatives, SRU/SRW and SOLR servers exposing Lucene indexes. It is, however, equipped to handle a broad range of different server behavior, through configurable query mapping and record normalization. If you develop configuration, stylesheets, etc., for a new type of resources, we encourage you to share your work. But you can also use Pazpar2 to connect to hundreds of resources that do not support standard protocols.
For a growing number of resources, Z39.50 is all you need. Over the last few years, a number of commercial, full-text resources have implemented Z39.50. These can be used through Pazpar2 with little or no effort. Resources that use non-standard record formats will require a bit of XSLT work, but that's all.
But what about resources that don't support Z39.50 at all? Some resources might support OpenSearch, private, XML/HTTP-based protocols, or something else entirely. Some databases exist only as web user interfaces and will require screen-scraping. Still others exist only as static files, or perhaps as databases supporting the OAI-PMH protocol. There is hope! Read on.
Index Data continues to advocate the support of open standards. We work with database vendors to support standards, so you don't have to worry about programming against non-standard services. We also provide tools (see SimpleServer) which make it comparatively easy to build gateways against servers with non-standard behavior. Again, we encourage you to share any work you do in this direction.
But the bottom line is that working with non-standard resources in metasearching is really, really hard. If you want to build a project with Pazpar2, and you need access to resources with non-standard interfaces, we can help. We run gateways to more than 2,000 popular, commercial databases and other resources, making it simple to plug them directly into Pazpar2. For a small annual fee per database, we can help you establish connections to your licensed resources. Meanwhile, you can help! If you build your own standards-compliant gateways, host them for others, or share the code! And tell your vendors that they can save everybody money and increase the appeal of their resources by supporting standards.
There are those who will ask us why we are using Z39.50 as our switchboard language rather than a different protocol. Basically, we believe that Z39.50 is presently the most widely implemented information retrieval protocol that has the level of functionality required to support a good metasearching experience (structured searching, structured, well-defined results). It is also compact and efficient, and there is a very broad range of tools available to implement it.