Trisquel GNU/Linux is a fully free operating system endorsed by the FSF. It has an educational edition, based on Ubuntu LTS, and also a stand alone Live/Installable image for CD and USB drives, based on the latest Ubuntu version. More info: http://trisquel.info/en/trisquel-sugar
You can download the (430MB) iso image from here:
To create a live USB disk with user data persistence, you can burn the image in a CD and use it to start a live session. Then plug the USB unit, open the terminal, and run "usb-creator". A launcher application is coming.
The usb-creator helper is also included in the Trisquel (and Ubuntu) desktop applications. If you use a different GNU/Linux distribution or Windows, you can use FUSBi instead.
Installing Sugar on Trisquel 2.2 LTS
To install the Sugar desktop you will need to add the repository to your apt configuration running this
echo "deb http://us.archive.trisquel.info/trisquel sugar-robur main" | sudo tee -a /etc/apt/sources.list sudo apt-get update
Now you can install the sugar-platform package using the synaptic package manager or by running
sudo aptitude install sugar-platform
You can now log out of your session and login into Sugar. If your computer is a LTSP server, it would be serving Sugar already.
Configure a Trisquel edu LTSP server
You can follow the instructions in the Trisquel wiki.
Installing Sugar on Trisquel 3.0
You can install Sugar with the above method, but using this repository line instead:
echo "deb http://us.archive.trisquel.info/trisquel sugar-dwyn main" | sudo tee -a /etc/apt/sources.list sudo apt-get update
Post bugs to official Trisquel bug tracker.