Just released an update to support both Java 7 and 8! (Check the OP.) Also included much better installation instructions in the download. Still working on updating the mod for Technic, however, so stay tuned for that... (UPDATE: Technic build is up! Woohoo!)
It was a surprisingly large amount of work, but things should hopefully remain playable for a good while to come. I recommend everyone keep a copy of Java 8 on their machine for the foreseeable future, not just for Hack/Mine, but for any old mods you may want to revisit some day.
The Meaning of Life, the Universe, and Everything.
I've loved this mod since I started playing it; just started a new world. However, it seems that mob spawning is still ridiculously high (I always have at least 1,000 entities shown in the debug screen, and sometimes it reaches over 10,000), even though the changelog indicates that this problem had been fixed. Perhaps this problem is there because I'm playing on Normal render distance?