Trisquel is a GNU/Linux distribution based on Ubuntu and recognised by the FSF (Free Software Foundation). It reuses Ubuntu packages and avoids using non-free packages. Thus, it uses the linux-libre kernel (like Parabola Linux).
A new version development begins just after an Ubuntu release. You have to wait about six months for the corresponding Trisquel version to be released.
Trisquel's base version uses a GNOME desktop. Other versions are available among which the Trisquel Mini version using an LXDE desktop.
The easiest way is to use the Triquel Mini version. One can install it with the "trisquel-mini" package, if needed, thanks to the command below.
There also exists a "lxde"-named package that can be installed thanks to the command below.
Here is the address to download Trisquel images: http://trisquel.info/en/download.