 In March 2006, Owen O’Malley was the first committer to add to the Hadoop project; Hadoop 0.1.0 was released in April 2006.It continues to evolve through contributions that are being made to the project.Hadoop consists of the "Hadoop Common" package, which provides file system and operating system level abstractions, a MapReduce engine (either MapReduce/MR1 or YARN/MR2) and the Hadoop Distributed File System (HDFS).