No.

The game's code base is proprietary, and Adams has stated he has no plans to release it into the open-source domain, citing the risk of them going into financial trouble.

He explained he would consider releasing its source if he could not maintain it anymore, seeing different game developers taking it up. He says that he does not mind any modifications as long as he is not put at financial risk.

It should be noted though, that if people followed OP in actually financially contributing to FOSS projects, then DF would likely have been made FOSS by now. His main fear is not having financial stability if he open sources his game.