for example, what is Pointer? what is Arena?

WASM is one of the supported platforms in Kotlin Native, where Pointer (was that supposed to be CPointer?) and Arena are handled. CPointer ( https://github.com/JetBrains/kotlin-native/blob/master/INTEROP.md#pointer-types ) represents a C Pointer, and Arena is a area where heap memory is allocated/freed in a Kotlin Native program/library ( https://kotlinlang.org/api/latest/jvm/stdlib/kotlinx.cinterop/-arena/index.html ).

it confuses me that Pointer, Arena and ArenaManager are redefined in the kotlinx.wasm.jsinterop package

Best to wait for WASM support in Kotlin Native to evolve into something more tangible where the basic JS interop is reasonably solid.

originally I wanted to do some graphics things with Kotlin WebAssembly, but it turns out that pure WebAssembly can't utilize GPUs, and calling WebGL is a great pain