Sites Using Drupal + Apache Solr: Combining Content Management and Enterprise Search

Drupal and ApacheSolr are a great combination. Drupal provides the infrastructure for managing content, taxonomies, and users. Solr provides a scalable, high performance search index, allowing results to be dynamically faceted so users can narrow down their results.

While there are plenty of examples of major websites using Solr, such as LinkedIn, Netflix, and Zappos, it's harder to find examples of sites using ApacheSolr and Drupal. I've put together a list of websites that combine both open source technologies. I think these are good examples of what an attractive, useful Drupal search interface can look like.

Open Magazine

The Open Magazine search interface allows users to search within a certain field. The search box also gives users a clear choice between searching within the results and starting a new search. This is a huge improvement over the default 'retain search filters' checkbox. The results themselves are compact and nicely themed. (Case Study)

Telenet Online Support

The Telenet Online Support website is multilingual and has a search interface that works in both French and Dutch. It also has an autocomplete feature, powered by the Apachesolr Autocomplete Module. (Write-up on buytaert.net)

Visualizing.org

Visualizing.org has a very attractive search interface. The filters are presented in a two-column layout to maximize their visibility. The results themselves are custom themed to include the star-rating and CCK fields for each result. (Case Study)

Merritt College

The Merritt College website uses the Open Scholar distribution and uses ApacheSolr to search across their multi-site installation of Drupal. (Case Study)

New York Public Library

The New York Public Library search interface is powered by ApacheSolr, although the library's catalog search is on a separate platform. The search form includes a tab so users can switch from searching the library website to searching the catalog. (Case Study)

Human Rights Watch

The Human Rights Watch search interface includes keyword highlighting. The search index includes a huge amount of content, which is easily accessible using the faceted search filters available.

Opensource.com

The Opensource.com search index is delivered by Acquia search, a hosted search solution. (Case Study)

AllHotels.com

The search interface for the AllHotels.com CMS includes a 'Related Destinations' block. This allows users to find landing pages related to their search, even though the landing pages don't have any text fields. (Case Study)

McGIll University Health Centre

The McGIll University Health Centre search interface users ApacheSolr with an Ajax interface, to allow users to facet search results without refreshing the page. It also includes a tabbed interface for search different content types (Case Study)

There's definitely a trend towards using the ApacheSolr module. While Acquia Search makes using ApacheSolr easy by providing a hosted solution, there is plenty of documentation available about integrating ApacheSolr with Drupal and hosting the search index locally. As more Drupal shops start embracing Solr, the list of good examples to draw from will grow. We've been using Solr for all our recent projects (the last two websites on the list above were built by Evolving Web) and strongly recommend it to all our clients. You can find more examples of sites using ApacheSolr on drupal.org. If you have more examples to add to the list, please share them in the comments.