From the author:

I've been working on a tool for brute-forcing Bitcoin private keys. The main purpose of this tool is to contribute to the effort of solving the Bitcoin puzzle transactions: https://blockchain.info/tx/08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15

There's also some good discussion here: https://bitcointalk.org/index.php?topic=4453897.msg39845999#msg39845999