Comment by herohamp
5 years ago
Portability. Say I wanted to make language X run on all platforms, but I didn't actually care about compiling it on all platforms. I can just write a relatively simple VM for each platform. This is one of the reasons Java was and still kinda is so ubiquitous
Wouldn't writing an interpreter for each platform be less work and achieve the same goal as writing a VM for each platform?
Edit: ^Aside from being able to execute the bytecode on any platform
Why would it be less work? The interpreter will need to implement whatever operations a VM can perform, so a priori it's at least as much work. Bonus, if you can bootstrap the source->bytecode process, then you only need to write (and compile) that once to get a full-fledged interpreter on every host with a VM
As others mentioned, source code should be distributed that way, and I think creating a simple VM is easier than a simple language parser. But of course, an optimizing one can be really quite complex in both cases.