An open source project from the Apache Software Foundation that provides a software framework for distributing and running applications on clusters of servers. Inspired by Google's MapReduce programming model as well as its file system, Hadoop was originally written for the Nutch search engine project. The name comes from a favorite stuffed elephant of the son of the developer George Cutting.

In early 2008, Yahoo! launched Yahoo! Search Webmap, the first, very large implementation of Hadoop, running on 10,000 Linux servers. The application is a core search engine technology, which runs in a third less time than Yahoo!'s previous system. See Google File System and MapReduce.