I heard there is a new (Lightweight) Desktop environment available named as LXQt for Ubuntu and I would like to know how can I install it on Ubuntu 14.04.
To install LXQt in Ubuntu 14.04 LTS open your terminal and paste these commands one by one.
sudo add-apt-repository ppa:lubuntu-dev/lubuntu-daily
sudo add-apt-repository ppa:gilir/q-project
sudo apt-get update
sudo apt-get install lxqt-metapackage lxqt-panel openbox
that will install LXQt in your Ubuntu 14.04 LTS.
FYI: Currently there are many bugs. So don't try if having a stable and reliable system is a requirement for you.
