Ubuntu 18.04 LTS aka Bionic Beaver is out today (April 26, 2018) and you can download it here.
After downloading it, go to the folder and do a shasum check to ensure your download’s integrity.
Here’s how to do the shasum check:
$ sha256sum bionic-desktop-amd64.iso adf9c1cbb2529cb06a67bbb16af881d8d918078e7e155a897ac30a9e0cf2bafa bionic-desktop-amd64.iso
Since this is a LTS (long term support) version, users of Desktop, Server and Core editions will get support in terms of security and other updates for the next five years, i.e., until April 2023.
I’m not a stranger to Ubuntu 18.04 LTS since I had already downloaded beta 2 (desktop version) a few days back on a Dell Optiplex 780 PC and launched it via Virtualbox.
Here are my first impressions of the official release of Ubuntu 18.04 LTS, which hews close to beta 2.