Since Java interop was a #1 priority w/ Kotlin, it has the same library support that Java does. Almost all of the major libraries just work.

Lately bigger players have started to take notice:

https://spring.io/blog/2017/01/04/introducing-kotlin-support...

https://blog.gradle.org/kotlin-meets-gradle

I'm still not sure where it will end up, but things look pretty good right now.

But wrt Type Erasure, Kotlin doesn't completely get rid of it; but it does offer some ability to retain Types in some generic situations.