In reality, with their millions, there's nothing stopping them from re-Lisping it. (Not even time considerations -- when they were in negotiations to be acquired, they didn't do any development for months [1]. If you can get away with spending that much time not developing before you have money, you can get away with doing a rewrite after money is no longer a concern.)

[1] "We must have stopped doing real work for six months." -- http://aaronsw.jottit.com/howtoget