Small update for Multiboot-v3:
First of all, the program doesn't really let you do anything unless you already have a usb drive formatted to FAT32 plugged in, so might as well do that now.
cd /tmp (it has to be /tmp)
wget http://liveusb.info/MultiBoot-v3/MultiBoot-v3.tar.bz2
tar xjf MultiBoot-v3.tar.bz2
rm MultiBoot-v3.tar.bz2
cd MultiBoot-v3
sudo ./install.sh
And it'll tell you pretty clearly which packages you need. Only confusing ones are "convert" and "identify" which are part of imagemagick, so if you need either of those, get imagemagick from your preferred package manager.
Assuming you have all the packages, a popup in french (a small one with just one button) might popup. Just hit enter. The next window to open should have a bit more stuff in it including an entry with your plugged in usb drives. This is the program itself, and can be accessed from a .desktop file on your desktop(possibly with some warning about trust in Ubuntu) as well.
How to switch from French:
Double click the entry or highlight it and click "Valider".
Open the top right dropdown "Menus" and click "Internationalisation".
Click the dropdown that says "French" and change it your language.
Press "Changer de language"
It's now in that language.
Like I said, just a small update, so you'll have to figure the rest out for yourself, but you're smart, I'm sure you'll do fine... Good luck!
