Having closely followed these threads, plus based on some private correspondence, my gut reaction is that there is no system discussed so far which meets all of the following criteria:
in reply to Perl 5 Optimizing Compiler, Part 4: LLVM Backend?
- handles all (or practically all) existing Perl syntax and semantics;
- doesn't require modification of existing Perl source (e.g. requiring you to add type declarations);
- provides an order-of-magnitude speed-up for general Perl code; (e.g. 5X rather than 10%);
- doesn't require a huge coding effort (of a similar magnitude to implementing parrot and perl6)
I'm not saying at this point that all of the proposals definitely fail these criteria; rather that no-one has yet explained any proposal to me in such a way that I have a real "Ooh I see how that might work!" epiphany; and my suspicion is that no-one ever will.