Do prisons let prisoners contribute to free software? It seems like it'd be a win for everyone: prisoners get something productive to do; the world get better software; prisons get to brag about providing opportunities for what amounts to career training, but without having to spend very much.

There's a long history of having prisoners clean roads and make license plates. I imagine that'll still happen, since not everyone has the temperament for technology. But why not let those who do have the temperament do something that society values?