It is in the Moose repository because Moose was essentially the first larger user (besides Helvetia) since its inception (more than 3 years now), and because the development of PetitParser was taken care of by the Moose team.

If others want to contribute (and even integrate into Pharo), it would be great and then we should move it. But, moving should come with commitment. This is an important piece in Moose and we need it to stay working and compatible with Moose requirements.

Cheers,

Doru