Eric S. Raymond「GPLはこれ以上必要ない」

ESR: GPL No Longer Needed

One of my heretical opinions is that we worry way too much about licensing. And in particular; I don't think we really need reciprocal licensing. I don't think we need licenses like the GPL, that punish people for taking code closed-source,

さらにESRは、「GPLの代替手段としてはBSDライセンスがいい」と付け加えたとのことです。