The Parrot backend was used to nail down the object system.
That's not how I remember things. Jonathan may have implemented the current object system on Parrot, but then he prototyped one on the CLR and one on the JVM (or vice versa), then wrote one for Rakudo based on that.
Concurrently, they are developing their own VM to get rid of the semantic mismatch between the language runtime and backend VM.
That's a very charitable interpretation of what they're doing.
Parrot started in 2001, and there was at least one P6 implementation in the works shortly after:
https://github.com/parrot/parrot/commit/9bb281bf85088000ee40...
The Parrot backend was used to nail down the object system.
That's not how I remember things. Jonathan may have implemented the current object system on Parrot, but then he prototyped one on the CLR and one on the JVM (or vice versa), then wrote one for Rakudo based on that.
Concurrently, they are developing their own VM to get rid of the semantic mismatch between the language runtime and backend VM.
That's a very charitable interpretation of what they're doing.