The Jetbrains Kotlin compiler in Eclipse outputs to a hidden folder inside the Eclipse compiler plugin. This hidden folder is then made available through the Eclipse Kotlin clas
Currently, this is not possible in the Kotlin Eclipse plugin.
To make it possible that Kotlin code can be used from Java, Kotlin plugin produce so-called lightweight class files to this folder. These class files do not contain bodies for methods and they are stored in memory.
Actual class files, that are used to run an application, are being built only before launch and they are produced to the default output folder. For now, we cannot produce class files on each save reasonably fast as there is no incremental compilation in the plugin yet: Feel free to upvote for this issue.