An open source Java-based tool for real-time big data processing. GridGain is an alternative to Hadoop’s MapReduce that is compatible with the Hadoop Distributed File System. It offers in-memory processing for fast analysis of real-time data. The open source version can be freely downloaded or you can choose to purchase a commercially supported version. GridGrain requires Windows, Linux or the Mac OS X operating system.
See also 50 Top Open Source Tools for Big Data on Datamation.