Notebook interface for everything

Zeppelin provides a unified interface for nearly all the major data process engines, including Spark. I quickly set it up on a virtual machine and gave it a test run. It works great.

This one has SparkR support built-in.

I was never really into the ipython/jupyter notebook mainly because there is nothing they can do that a good IDE such as PyCharm or Rodeo cannot. Zeppelin is different because its capability of tightly integrating different Spark front-ends, including Scala, Python, and R is uniquely powerful. I would call this revolutionary.

R Users Will Now Inevitably Become Bayesians

Good post here. I would also add that the rethinking package is a third option that helps R users to become a Bayesian.