ecru consists of the ecru (electronic course reserves unleashed) database, an instance of Apache Solr 4.*, which backs a robust RESTful API pattern set for querying the books, articles, and weblinks that are "reserved" for a particular course.
At Harvard, a job that updates the ecru database with data from the Reserves List System (aka the "Reserves Tool") runs frequently, but the underlying ecru software is designed to support reserves data from other sources as well.
Let your cursor linger over each of the choices below to see the underlying API pattern endpoint.