At JetBrains we're using Kotlin on a few projects now. Some of them are internal, some are public facing. In addition, some of our existing (and new) products are now using Kotlin. IntelliJ IDEA 15 will be shipping with Kotlin plugin enabled by default.
Kotlin is a tool we created out of need. We're using it and we're relying on it, so I'd say it's got a very good long term viability.
Kotlin is a tool we created out of need. We're using it and we're relying on it, so I'd say it's got a very good long term viability.