Depends entirely on locale where the publishing occurs.
Chances are above average, regardless of location, that if the reversing was rendered for profit and not for "compatibility" reasons the author may be subject to litigation. Honestly, in this day and age, the person will likely be subject to litigation regardless of purpose if the target is big enough and the application valuable enough by the original authors.
Tread lightly and carefully would be the best advice that could be given. Really have to verify local laws.
Again, I say all this sans a JD, thus it should be taken with a grain of salt.
Did you circumvent protections for copyrighted material? Are you documenting how to do so? If not, then the DMCA does not apply?
Did you agree to a license that forbids reverse engineering the software, either when you opened the package or when you installed the software? If so, then you could be in trouble, though I don't think such shrink wrapped licenses have ever really been challenged in court.