Yeah, I've considered playing with Quasar, but I'm a bit concerned about the "colored functions" that it imposes. In any case, I'm mainly interested in Fibres as a code generation platform (for some toy languages I'm playing with), and obviously there I could avoid having to use Quasar/bytecode rewriting by simply emitting functions as state machines in the first place... My hope for project Loom is to be able to avoid this, i.e. to have it taken care of automagically by JVM.