GCing is a concern, yes. With the Binary Data API and some extensions, it might be possible down the road to have GC'd objects in asm.js compiled code. Definite

GCing is a concern, yes. With the Binary Data API and some extensions, it might be possible down the road to have GC'd objects in asm.js compiled code. Definitely an interesting area to investigate. Multhreading is another concern, if you want shared state (with the JVM would need). It can't currently be done, but again, is worth thinking about and perhaps new web APIs could enable it some day.