Oliver Crisp mentioned that Donald Macleod endorsed “Libertarian Calvinism.” I briefly searched around the Interwebs and found this blurb by Macleod,
Neither of these statements is more careful or more evangelical than that of the Westminster Confession: ‘God from all eternity did, by the most wise and holy counsel of his own will, freely and unchangeably ordain whatsoever comes to pass: yet so, as thereby neither is God the author of sin, nor is violence offered to the will of the creatures, nor is the liberty or contingency of second causes taken away, but rather established.’ This allows (indeed, requires) us to distinguish sharply between predestination and determinism. It also relates suggestively to the open universe described by modern physics. An event can be predestinated, yet free: indeed, it is predestination that guarantees freedom. Similarly, an event can be predestinated and yet contingent. Such, at least, was the perspective of Westminster Calvinism, leaving its adherents to be libertarians and indeterminists if that was where their phisophical predilections and scientific investigations led them.