input: [Title] PhilPapers [Description] 
output: [Description below provided by the database producer] What is PhilPapers? PhilPapers is an online research hub in philosophy that combines the following four services: A publication index of philosophy journal articles, book reviews, books, and book chapters in all languages. An open access aggregator that indexes open access philosophical content found on over one thousand open access archives and three thousand personal pages maintained by professional philosophers. An open access archive that hosts the largest collection of open access philosophical material on the Internet (OAI-PMH handler here). A structured bibliography comprising nearly five thousand subcategories covering all subjects in philosophy. PhilPapers allows philosophers to search, browse, and monitor the above content seamlessly through a unified interface. The contents of PhilPapers' indexes and bibliographies are maintained by thousands of academics who volunteer their time. Over four hundred academics are officially appointed as Category Editors.