But its concurrency uses green threads only, no proper multicore support? That's such a pity. Lack of built-in parallel programming facilities is a big problem

But its concurrency uses green threads only, no proper multicore support? That's such a pity. Lack of built-in parallel programming facilities is a big problem of many otherwise nice languages, many scheme implementations have this limitation, too. A relatively new programming language should really use all cores, ideally it should distribute the green threads across the available cores with its own scheduler automatically and have synchronization primitives like channel work across them.