> I wonder where we’d be if the idea of CPU-independent bytecode had ever really taken off [...] convert it to the actual machine code, about which the OS might

> I wonder where we’d be if the idea of CPU-independent bytecode had ever really taken off [...] convert it to the actual machine code, about which the OS might know nothing, and could vary incompatibly from CPU to CPU, even among different CPU models in the same family There are various examples I can think of. Nvidia's CUDA platform compiles C++-like source code to PTX binary code which is GPU-independent. At run time, PTX is compiled and specialized for the specific GPU model you are running on. I can imagine that PTX is compiled differently depending on the number of registers in the GPU as well as its instruction set capabilities. https://en.wikipedia.org/wiki/Parallel_Thread_Execution https://en.wikipedia.org/wiki/Parallel_Thread_Execution Mainstream virtual machine languages like Java, .NET, and JavaScript are obvious examples.