Ovid led the specification effort and did all the boring writing it up stuff because he wanted it to exist, Stevan Little (author of Moose) originated the idea but got distracted by real life before he got it finished, a bunch of us (including me quite a bit and even Damian Conway briefly) with a shitload of OO system design experience consulted and suggested and gave feedback.
LeoNerd (Paul Evans) I believe did a bunch of the code for both p3rl.org/Object::Pad (which was significantly an on-cpan prototype for this work) and the 'class' feature on his own time and also a bunch of it via sponsorship, though I'm less confident of the details there because since I can't write C to save my life I spent my tuits on the design and cat herding side and just assumed LeoNerd would get it right.
(the same approach worked out pretty well during the period he was doing dev work for me at https://shadow.cat/ too and we still keep an open contract with him in case we run into a LeoNerd-shaped problem, he is Just That Good IMO)
LeoNerd (Paul Evans) I believe did a bunch of the code for both p3rl.org/Object::Pad (which was significantly an on-cpan prototype for this work) and the 'class' feature on his own time and also a bunch of it via sponsorship, though I'm less confident of the details there because since I can't write C to save my life I spent my tuits on the design and cat herding side and just assumed LeoNerd would get it right.
(the same approach worked out pretty well during the period he was doing dev work for me at https://shadow.cat/ too and we still keep an open contract with him in case we run into a LeoNerd-shaped problem, he is Just That Good IMO)