Ambra also ties in to a number of other open-source applications. PLOS developed the Article-Level Metrics (ALM) application to display information about the usage and reach of published articles on the articles themselves. PLOS uses the ALM application to aggregate relevant data and statistics for research articles including online usage, citations, social bookmarks, notes, comments, ratings, and blog coverage. Solr is used for its search platform, Apache Camel for syndication of articles to external websites, CAS (Central Authentication Service) for single sign-on, and MogileFS as a distributed file system.
All PLOS journals and PLOS Collections are hosted on the Ambra platform, with the only exceptions being PLOS Hubs: Biodiversity, which uses the Liferay Portal platform, and PLOS Currents, which is currently hosted on Google Knol.
In two recent developments (Summer 2011), PLOS launched Search and Article-Level Metrics APIs to encourage the creation of apps that will improve the way PLOS users discover and interact with our (and their) content. We even joined forces with Mendeley, the popular reference manager and academic social network, to launch a Binary Battle (developers competition) that encourages the creation of apps that make science more open.