Since the goal of Kotlin was for use in improving their products, it focuses very strongly on interop with Java code and the Java standard library. The Kotlin language was created in response to limitations in Java which were hindering development of JetBrains’ software products and after an evaluation of all other JVM languages proved unsuitable. Kotlin is a language by JetBrains, the company behind IntelliJ IDEA and other tools, and is purpose built for large-scale software projects to improve upon Java with a focus on readability, correctness, and developer productivity.

Since acquiring the Android operating system, Google has invested heavily in tuning and optimizing compilation and runtime environments for running Java-based code on Android devices. Until the introduction of Kotlin, it is quite likely that every Android app available on the market was written in Java. Originally introduced by Sun Microsystems in 1995 Java is still by far the most popular programming language in use today.

In terms of safety, Kotlin includes a number of features that improve the chances that potential problems will be identified when the code is being written instead of causing runtime crashes.

Kotlin code online