You don't want a brute forcer for minecraft, I recommend Eggcrack, and I have a great tutorial of how to use it.
Now, to why you don't want a brute forcer:
Minecraft passwords can be 6-26 characters long, in ASCII
ASCII has 128 characters total
So, 26^26 = ((10^39) * 8)
Also knows as 8 dudecillion.
After that, there are many other types of characters, such as:
sıɥʇ
So it would be about 16 dudecilion with the addition of up-side-down words, and then there are many, many more.
Also, if you tried google these things, you'd get many hits.
Google is your friend.