When comparing Chromium OS vs Adélie Linux, the Slant community recommends Chromium OS for most people. In the question“What are the best Linux distros that don't use systemd?” Chromium OS is ranked 35th while Adélie Linux is ranked 41st. The most important reason people chose Chromium OS is:
Since you only have the browser, you cannot install applications (outside Chrome Apps which are decently protected by their limited API and the Chrome Web Store). This means no harmful virus, and also nearly no way you can screw your system. Everything will just work.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Safe and requires little to no maintenant
Since you only have the browser, you cannot install applications (outside Chrome Apps which are decently protected by their limited API and the Chrome Web Store). This means no harmful virus, and also nearly no way you can screw your system. Everything will just work.
Pro Minimalistic interface
Chromium's system UI uses as little screen space as possible by combining apps and standard web pages into a minimal tab strip: While existing operating systems have web tabs and native applications in two separate strips, Chromium OS combines these, giving access to everything from one strip. The tab is the equivalent of a desktop application's title bar; the frame containing the tabs is a simple mechanism for managing sets of those applications and pages.
Pro Lightweight
Because Chromium OS is designed for users who spend most of their computer time on the Web, it is intended for use in computers with little local storage and fast boot-up times.
Pro Simple packaging system
Built on Alpine's APKBUILD system, which is an accessible and simple packaging system. If you're familiar with Arch's ABS or Gentoo's ebuilds, APKBUILDs are a breeze.
Pro Is pure Python 3
There is a hard and fast rule against Python 2 software in the main repositories, with efforts focused on adapting software to use Python 3 where possible.
Pro Small and performant
A standard installation takes under 200 MB. Only the bare necessities are included.
Pro Inviting and receptive development team
The people building the distro are knowledgeable and helpful when issues arise. Merge requests are actively suggested and reviewed, and the developers thank users for taking the time to learn the distro.
Cons
Con Google
Possibly harms your privacy.
Con Made for developers
ChromiumOS is mainly made for development, so there exist no official install images and you have to build it from source or use third party images like Arnold's or the waterfall images.
Con No auto-upgrade (unlike Chrome OS)
Chrome OS auto-upgrade the system, but Chromium OS does not. It's possible that they're thinking about adding that feature from the design doc.
Con Not (yet) ready for Linux newbies
As of November 2018, there isn't an installer yet. If you're familiar with installing Arch or Gentoo (via chroot, fdisk, et al) then it's no big deal. An installer framework (called Horizon) is in the works.
Con Is pure Python 3
Python 2 support is not supported by the distro, so many older upstreams who haven't adapted to Python 3 yet will need their software patched to work (this is both a pro and a con).
Con Somewhat limited package set for servers
As of November 2018, it's still missing some server software. It's primarily a desktop-oriented distribution, but accepts server packages and progress has already been made on that front, including lighttpd, apache, and php-fpm. Contributors are already bringing more server software to the distro, including certbot, cgit, and Nextcloud.
