These steps document how to install elementary OS Daily - which includes the latest bells and whistles of elementary OS development.
You need to add the elementary OS Daily PPA to enable your elementary OS to find the latest available packages. For this, open a Terminal and insert the following commands:
sudo apt install software-properties-common # installs the "add-apt-repository" command sudo add-apt-repository ppa:elementary-os/daily sudo apt update sudo apt upgrade
Et voilà, your on elementary OS Daily now!
For more details see the PPA’s homepage.
If you plan to develop for elementary OS, then you also need to install the elementary OS SDK:
sudo apt install elementary-sdk