The (meta)data underneath SearchWorks is largely based on our MARC records from Symphony. MARC records are exported from Symphony, then slurped up by an application called SolrMarc, which transforms the MARC data into an index for the Solr search engine used by SearchWorks.
SolrMarc is open source software made available by Bob Haschart of the University of Virginia Libraries. SolrMarc is used by all(?) VuFind sites as well as most Blacklight sites built on MARC data (e.g. SearchWorks). SolrMarc has been great for us -- it gave us an enormous jump start for SearchWorks. Bob is also a great guy, and made me a "committer" almost immediately -- so I can make contributions to the open source code.
Open Source Software does best when there is a critical mass of developers: group wisdom rocks, as does sharing the work. To date, SolrMarc is very much Bob's project, despite a number of committers such as myself. There are some ... interesting ... practices as to how SolrMarc is organized and how it is tested. I've even contributed a bit to some of its squirreliness. Occasionally, changes to the SolrMarc codebase break the code I've written especially for Stanford.