Certainly trapping overflow is progress, but it's not that hard to implement unbounded integers such that the common case (small integers) are just as efficient

Certainly trapping overflow is progress, but it's not that hard to implement unbounded integers such that the common case (small integers) are just as efficient as the modulo arithmetic we use today. Sun's SPARC even included hardware support for this (TADDcc, TSUBcc), but programming languages didn't exploit it and the support was removed. This will only change once there's enough demand that supporting it in hardware becomes a competitive advantage. There's plenty of precedence for this, eg. various crypto support in x86, the evolution of GPUs, networking accelerators, etc. I intend to change Reduceron to use unbounded integers by default so that the promise that "Well typed programs don't go wrong" isn't a blatant lie.