Implementor Question

[Peter Hall]

> But again, two engines don't cut it, for footprint and memory
> reasons. And two engines are intentionally unnecessary by the design
> of ES4.
>

Not to mention the pains of making the two engines interoperable. In
Flash, the new VM is not compatible with the old, and you have to go
to extreme lengths to communicate between the two. Using one VM in
Flash is much harder problem because the compiler is separate, AS2 was
not completely compliant, and the files are already compiled into
incompatible formats when they are loaded. Flash developers are
dealing with that when it crops up, but the wider web can't be
expected to do that, and it doesn't make sense to push that burden
onto browser manufacturers either.

Peter