An open source software abstraction layer for Hadoop, Cascading allows users to create and execute data processing workflows on Hadoop clusters using any JVM-based language. It is intended to hide the underlying complexity of MapReduce jobs. Cascading was designed by Chris Wensel as an alternative API to MapReduce. It is often used for ad targeting, log file analysis, bioinformatics, machine learning, predictive analytics, Web content mining and ETL applications. Commercial support for Cascading is offered by Concurrent, a company founded by Wensel after he developed Cascading. Enterprises that use Cascading include Twitter and Etsy. Cascading is available under the GNU General Public License.