Kotlin is a сonсise, safe, interoperable, and tool-friendly programming language. Kotlin targets different platforms: Server, Android™, Browser, Native, and allows the business logic code to be shared across them. Some facts on Kotlin in 2018: 1.5M+ developers from all over the world edited Kotlin code in 2018 100M + Lines of Kotlin code Android — 1 in 4 apps (from top 1000) uses Kotlin

Pinterest has successfully introduced Kotlin into their application, used by 150M people every month. https://www.youtube.com/watch?v=mDpnc45WwlI Gradle is introducing Kotlin as a language for writing build scripts. https://blog.gradle.org/kotlin-meets-gradle Evernote recently integrated Kotlin into their Android client https://blog.evernote.com/tech/2017/01/26/android-state-library/ Uber team uses Kotlin for building internal tools https://www.reddit.com/r/androiddev/comments/5sihp0/2017_whos_using_kotlin/ddfmkf7/ Coursera Android app is partially written in Kotlin https://building.coursera.org/blog/2016/03/16/becoming-bilingual-coursera/ All new code in the Trello Android app is in Kotlin. https://twitter.com/danlew42/status/809065097339564032 There are also some books on Kotlin: https://kotlinlang.org/docs/books.html These are far from all, just a couple of recent ones.