There is not much difference between Horton and Cloudera, Cloudera is more stable, but lags behind in features. Horton in its turn includes new features in their releases more aggressively, but sacrifices overall stability of distributive. Other than that, I would say there pretty much same. Cloudera has several proprietary products, like Impala and Cloudera Manager. Horton has only open source components.

MapR is interesting by their own distributed file system, it's written on C++, not Java and should be faster, more reliable and easy to use than HDFS. It also has more enterprise class features like volume support or point in time recovery.

Each company also use their own administrative and monitoring toolkits. I haven't seen MapR's version of the monitoring/admin tool, but Ambari (Apache/Horton) and Clouder Manager seemed pretty same to me. While admins say that Cloudera Manager is more comprehensive in term of features.

Станислав Клевцов,

вроде работает.