Apache Beam is a unified programming model for Batch and Streaming data
processing.

Beam provides a general approach to expressing embarrassingly parallel data
processing pipelines and supports three categories of users, each of which have
relatively disparate backgrounds and needs.

* End Users: Writing pipelines with an existing SDK, running it on an existing
  runner. These users want to focus on writing their application logic and have
  everything else just work.
* SDK Writers: Developing a Beam SDK targeted at a specific user community
  (Java, Python, Scala, Go, R, graphical, etc). These users are language geeks
  and would prefer to be shielded from all the details of various runners and
  their implementations.
* Runner Writers: Have an execution environment for distributed processing and
  would like to support programs written against the Beam Model. Would prefer to
  be shielded from details of multiple SDKs.