thank you for let a bit of time to answer my question. I readed the license and understood it a bit (but with my low english level I wasn't sure I understood it well). I'll read it again keeping in mind your aclaration.
I didn't improve any important modifications, I made only a few changes at source to use that great gui under the distribution I am using (like I said in my last post). I don't know if Nathan will read this post but I'll post here a link to my webpage where are located the changes. Only looking to the "sed" sentences wich are the few changes what I was talking about. Here is the link
I think the most important change is the line about changing the /root dir by $HOME to let users burn.
And the other change is the use of gtkdialog instead of the gtkdialog3 provided by puppylinux. I think this changes are not relevant to grafburn directly, but they are needed to use it under the distro wich I'm using.
At this link you can see the file's location at the "new system", and like you said, I keept the lincense inside.
Thank you a lot again for your time and patience.