Threading just doesn't work (it's going to be rewritten from scratch). Sometimes there are segfaults within managed code and sometimes there are memory leaks. Sometimes an assertion in the VM fails, causing the program to halt with a stack trace. A few releases ago the compiler of Parrot's assembly language reported wrong line numbers in error messages, but this has been fixed.

All those "sometimes" seems to suggest that Parrot is much more than a bit buggy.

A memory leak is one thing, but segfaults and assertion failures... Down to brass tacks: is this thing usable in its current state?

> Down to brass tacks: is this thing usable in its current state?

Experimentation and quick and dirty prototypes? Yes. Production code? No.