Thanks UR but is there a way to uncompress the whole file?

And what program do you use to open the file(or any other)?
Is it a hex editor?

I'm working on a jj wiki on wikia thats why i need some info on the jj2 files.

Oh and a question about the .j2b format.
Would i be able to play it whit any other program other then jj2 whit-out converting it?