Node.js v4 or later. Splunk logging for Javascript is tested with Node.js v10.0 and v14.0. Splunk Enterprise 6.3.0 or later, or Splunk Cloud. Splunk logging for Javascript is tested with Splunk ...
It is documented at windowjs.org. Window.js is distributed as a single binary that can be downloaded for Windows and macOS. It can also be built from the sources for Windows, macOS and Linux.