Among many improvements, this release has:
• Support for Java and Scala, including sharing classes with Groovy.
• Support for running Python2 and Python3 at the same time.
• A better method of finding and configuring language backends.
• Support for Processing via p5.js.
• New APIs for reflection, scripting, and dashboards.
• Works with old Mac hardware and old Mac operating systems.
• Standard output and error output now appear below the cell that produced them instead of in a unified panel.
• Too many performance and bug fixes to count.
