KNIME Desktop: the "killer app" for machine learning and statistics

If you work with data in any capacity, go ahead and do yourself a favor: download KNIME Analytics Platform right here. KNIME Analytics Platform is the strongest and most comprehensive free platform for drag-and-drop analytics, machine learning, statistics, and ETL that I've found to date. The fact that there's neither a paywall nor locked features means the barrier to entry is nonexistent. Connectors to data sources (both on-premise and on the cloud) are available for all major providers, making it easy to move data between environments. It's also worth mentioning that the community is particularly robust.