He actually meant "Kotlin instead of Apache Groovy". Groovy joined the Apache Software Foundation last November (2015), and its name should be qualified with the "Apache" brand on first use in a new context such as a webpage. Groovy joined the ASF after the 6 developers working on it and Grails were retrenched by VMware in March last year, and they couldn't find any other business to support their work on Groovy.
