MapR develops and sells Apache Hadoop derived software. They contribute to many Apache Hadoop related projects including HBase, Pig, Hive and ZooKeeper.
MapR entered a technology licensing agreement withEMC Corporation on 25 May 2011, supporting an EMC-specific distribution ofApache Hadoop.. In addition, MapR was selected by Amazon to provide an upgraded version of Amazon’s Elastic Map Reduce (EMR) service
MapR provides two versions of their product known as M3 and M5. M3 is a free version of the M5 product with degraded availability features.
Their Hadoop Distribution claims to provide full data protection with no single points of failure plus improved performance and ease of use. But with a very dynamic market it is hard to assess leadership in these areas and that leadership, if there, might not exist long term since this is a fast moving area.