Apache Storm is a free and open source real time analytics processing system that processes large volumes of analytics data (e.g. web logs, streaming sensor readings, activity feeds, ecommerce transactions) in real time. This is a departure from traditional Big Data tools such as Map Reduce which do similar analysis but through a batch processing approach.
Microsoft has announced that Apache Storm will be available as part of the latest version of the HDInsight Service.
Hortonworks has also added hybrid data connectors to enable hybrid scenarios where on-premise Hadoop deployments are backed up to the cloud on Azure or where additional on-demand bursting is needed beyond what is available on premise.