Pop! OS

Pop!_OS is a free and open-source Linux distribution, based upon Ubuntu, featuring a custom GNOME desktop. The distribution is developed by American Linux computer manufacturer System76. Pop!_OS is primarily built to be bundled with the computers built by System76, but can also be downloaded and installed on most computers.
Pop!_OS provides full out-of-the-box support for both AMD and Nvidia GPUs. It is regarded as an easy distribution to set up for gaming, mainly due to its built-in GPU support. Pop!_OS provides default disk encryption, streamlined window and workspace management, keyboard shortcuts for navigation as well as built in power management profiles. The latest releases also have packages that allow for easy setup for TensorFlow and CUDA.
Pop!_OS is maintained primarily by System76, with the release version source code hosted in a GitHub repository. Unlike many other Linux distributions, it is not community-driven, although outside programmers can contribute, view and modify the source code. They can also build custom ISO images and redistribute them under another name.
Features.
Pop!_OS primarily uses free software, with some proprietary software used for hardware drivers for Wi-Fi, discrete GPU and media codecs. It comes with a wide range of default software, including LibreOffice, Firefox and Geary. Additional software can be downloaded using the package manager. 
Pop!_OS uses APT as its package manager and initially did not use Snaps or Flatpak, but Flatpak support was added in version 20.04 LTS. Software packages are available from the Ubuntu repositories, as well as Pop!_OS's own repositories. Pop!_OS features a customized GNOME Shell interface, with a Pop!_OS theme.
There is a GUI toggle in the GNOME system menu for switching between different video modes on dual GPU laptops. There are three display modes: hybrid, discrete and iGPU only. There is a power management package developed from the Intel Clear Linux distribution. Pop!_OS uses Xorg as its display manager, with Wayland available optionally, as Ubuntu has done. Wayland lacks support for proprietary device drivers, in particular Nvidia, while Xorg is supported. To enable use of Nvidia proprietary drivers for most performance and GPU switching, Pop!_OS uses only Xorg to date.
TensorFlow and CUDA enabled programs can be added by installing packages from the Pop!_OS repositories without additional configuration required.
It provides a Recovery Partition that can be used to 'refresh' the system while preserving user files. It can be used only if it is set up during initial installation.
For the 21.04 release, System76 is developing a new GNOME-based desktop environment called COSMIC, an acronym for Computer Operating System Main Interface Components. It will feature separate views for workspaces and applications, a dock included by default, and will support both mouse-driven and keyboard-driven workflows.
Installation.
Pop!_OS provides two ISO images for download: one with AMD video drivers and another with Nvidia drivers. The appropriate ISO file may be downloaded and written to either a USB flash drive or a DVD using tools such as Etcher or UNetbootin. 
Pop!_OS initially used an Ubuntu-themed installer. Later it switched to a custom software installer built in partnership with elementary OS called Pop Shop which comes pre-installed with Pop! OS.
Release history.
17.10.
Prior to offering Pop!_OS, System76 had shipped all its computers with Ubuntu pre-installed. Development of Pop!_OS was commenced in 2017, after Ubuntu decided to halt development of Unity and move back to GNOME as its desktop environment. The first release of Pop!_OS was 17.10, based upon Ubuntu 17.10. In a blog post explaining the decision to build the new distribution, the company stated that there was a need for a desktop-first distribution. The first release was a customized version of Ubuntu GNOME, with mostly visual differences. Some different default applications were supplied and some settings were changed. The initial Pop theme was a fork of the Adapta GTK theme, plus other upstream projects. 17.10 also introduced the Pop!_Shop software store, which is a fork of the elementary OS app store.
Bertel King of "Make Use Of" reviewed version 17.10, in November 2017 and noted, "System76 isn’t merely taking Ubuntu and slapping a different name on it." King generally praised the release, but did fault the "visual inconsistencies" between applications that were optimized for the distribution and those that were not and the application store, Pop!_Shop, as incomplete. For users who may want to try it on existing hardware he concluded, "now that Ubuntu 17.10 has embraced GNOME, that’s one less reason to install Pop!_OS over Ubuntu."
18.04 LTS.
Version 18.04 added power profiles; providing easy GPU switching, especially for Nvidia Optimus equipped laptops; HiDPI support; full disk encryption and access to the Pop!_OS repository.
In 2018, reviewer Phillip Prado described Pop!_OS 18.04 as "a beautiful looking Linux distribution". He concluded, "overall, I think Pop!_OS is a fantastic distribution that most people could really enjoy if they opened up their workflow to something they may or may not be used to. It is clean, fast, and well developed. Which I think is exactly what System 76 was going for here."
18.10.
Release 18.10 was released in October 2018. It included a new Linux kernel, graphic stack, theme changes and updated applications, along with improvements to the Pop!_Shop software store.
19.04.
Version 19.04 was mostly an incremental update, corresponding to the same Ubuntu version. It incorporated a "Slim Mode" option to maximize screen space, through reducing the height of application window headers, a new dark mode for nighttime use and a new icon set.
Joey Sneddon of "OMG! Ubuntu!" reviewed Pop!_OS 19.04 in April 2019 and wrote, "I don’t see any appreciable value in Pop OS. Certainly nothing that would make me recommend it over regular Ubuntu 19.04 ..."
19.10.
In addition to incremental updates, version 19.10 introduced Tensorman, a custom TensorFlow toolchain management tool, multilingual support and a new theme based on Adwaita.
In a 2019 comparison between Pop!_OS and Ubuntu, Ankush Das of "It's FOSS" found that while both distributions have their advantages, "the overall color scheme, icons, and the theme that goes on in Pop!_OS is arguably more pleasing as a superior user experience."
20.04 LTS.
Pop!_OS 20.04 LTS was released on 30 April 2020 and is based upon Ubuntu 20.04 LTS. It introduced selectable auto-tiling, expanded keyboard shortcuts and workspaces management. It also added Pop!_Shop application store support for Flatpak and introduced a "hybrid graphics mode" for laptops, allowing operation using the power-saving Intel GPU and then providing switching to the NVidia GPU for applications that require it. Firmware updates became automatic and operating system updates could be downloaded and later applied while off-line.
In examining Pop!_OS 20.04 beta, "FOSS Linux" editor, Divya Kiran Kumar noted, "with its highly effective workspaces, advanced window management, ample keyboard shortcuts, out-of-the-box disk encryption, and myriad pre-installed apps. It would be an excellent pick for anyone hoping to use their time and effort effectively."
Jason Evangelho reviewed Pop!_OS in "FOSS Linux" January 2020 and pronounced it the best Ubuntu-based distribution.
A review of Pop!_OS 20.04 by Ankush Das in "It's FOSS" in May 2020 termed it "the best Ubuntu-based distribution" and concluded, "with the window tiling feature, flatpak support, and numerous other improvements, my experience with Pop!_OS 20.04 has been top-notch so far."
"OMG! Ubuntu!" reviewer Joey Sneddon wrote of Pop!_OS 20.04, "it kinda revolutionises the entire user experience". He further noted, "The fact this distro doesn't shy away from indulging power users, and somehow manages to make it work for everyone, underlines why so-called 'fragmentation' isn't a bad thing: it's a chameleonic survival skill that allows Linux to adapt to whatever the task requires. It is the T-1000 of computing, if you get the reference. And I can't lie: Ubuntu could really learn a few things from this approach."
In a 19 October 2020 review in "FOSS Bytes" by Mohammed Abubakar termed it, "The Best Ubuntu-based Distro!" and said it is, "an Ubuntu-based Linux distro that strikes a perfect balance between being beginner-friendly and professional or gaming use".
20.10.
Pop!_OS 20.10 was released on 23 October 2020 and is based upon Ubuntu 20.10. It introduced stackable tiled windows and floating window exceptions in auto-tiling mode. Fractional scaling was also introduced, as well as external monitor support for hybrid graphics.
"Beta News" reviewer Brian Fagioli in particular praised the availability of fractional scaling and stacking and noted "what the company does with Pop!_OS, essentially, is improve upon Ubuntu with tweaks and changes to make it even more user friendly. Ultimately, Pop!_OS has become much better than the operating system on which it is based."
Release table.
Pop!_OS is based upon Ubuntu and its release cycle is same as Ubuntu, with new releases every six months in April and October. Long term support releases are made every two years, in April of even-numbered years. Each non-LTS release is supported for three months after the release of the next version, similar to Ubuntu. Support for LTS versions is provided until the next LTS release. This is considerably shorter than Ubuntu which provides 5 year support for LTS releases. 