Enable themes on your odoo 8 server

To enable themes you must install Less CSS via nodejs.

On Linux, use your distribution’s package manager to install nodejs and npm.

Warning
In debian wheezy and Ubuntu 13.10 and before you need to install nodejs manually:

$ wget -qO- https://deb.nodesource.com/setup | bash -
$ apt-get install -y nodejs

In later debian (>jessie) and ubuntu (>14.04) you may need to add a symlink as npm packages call node but debian calls the binary nodejs

$ apt-get install -y npm
$ sudo ln -s /usr/bin/nodejs /usr/bin/node

Once npm is installed, use it to install less and less-plugin-clean-css:

$ sudo npm install -g less less-plugin-clean-css

on OS X, install nodejs via your preferred package manager (homebrew, macports) then install less and less-plugin-clean-css:

$ sudo npm install -g less less-plugin-clean-css

on Windows, install nodejs, reboot (to update the PATH) and install less and less-plugin-clean-css:

C:\> npm install -g less less-plugin-clean-css

Warning
You can have problems with NodeJS and NPM packages in the Ubuntu 14.04 repository because they are outdated.

Follow the instructions from the NodeJS Website:

curl -sL https://deb.nodesource.com/setup_0.10 | sudo bash -
sudo apt-get install -y nodejs
sudo npm install -g npm (to update npm)

Then install Less and accessories:

sudo npm install -g less less-plugin-clean-css