Comparison & List of Desktop Environments

The below table shows a comparison of the main desktop environments available for Linux and Unix, as well as the macOS and Microsoft Windows for the sake of comparability.

For Linux (and some Unix operation systems), there are the "Big Two" desktops, KDE and GNOME, as well as many smaller ones and the option of running a stand-alone window manager.

The desktop environment "landscape" has fragmented since the controversial initial release of GNOME 3 in 2011, which spawned a number of soft and hard forks as well as newly created desktops that are nevertheless based on some of GNOME technology or which were created out of disagreement with the GNOME developers; these include MATE (a continuation of GNOME 2), Linux Mint's Cinnamon (based on GNOME 3 tech), Solus's Budgie, elementaryOS's Pantheon, pop_OS!'s COSMIC, Ubuntu Unity's UnityX, Ubuntu Kylin's UKUI.

KDE only had one notable fork, Trinity, which is a continuation of KDE 3.

Other notable desktop environments not mentioned so far include Xfce, LXQt, Deepin Desktop, CDE, Lumina, as well as Enlightenment and its fork Moksha.

Comparison of Desktop Environments (short version)

Source: eylenburg.github.io

Last updated: 4 July 2025



General
License	GPL	GPL	GPL, LGPL, BSD	GPL, LGPL	GPL	GPL, LGPL	GPL, LGPL	Proprietary	Proprietary
First release	1998	1999	1997	2011	2011	2013	2013	2000	1995Windows 95
Forked from	-	-	-	GNOME 2	GNOME 3	LXDE & Razor-qt	-	-	-
Corporate and government backing	Blue Systems, Canonical, Google, Qt Group, SUSE	IBM (Red Hat), Canonical, Google, SUSE, System76	-	-	-	-	-	Apple	Microsoft

Application suite
Legend: KDE app or fork GNOME app or fork uses Qt uses GTK
GUI toolkit	Qt	GTK	GTK	GTK	GTK	Qt	GTK	Cocoa	WinUI
Window manager	KWin	Mutter	Xfwm4fork of Fvwm	Marcofork of Metacity	Muffinfork of Mutter	variousFor X11, the default is Openbox, but KWin and Xfwm4 are also available. For Wayland, there is a choice of Labwc, KWin, Wayfire, Hyprland, Sway, Niri and River.	Magpiefork of Mutter	Quartz Compositor	Desktop Window Manager
Preferred display manager	SDDM	GDM	LightDM	LightDM	LightDM	SDDM	LightDM	macOS login screen	Windows login screen
Embedded HTML engine	QtWebViewBlink, fork of WebKit, fork of KHTML	WebKitGTKWebKit, fork of KHTML	-	-	WebKitGTKWebKit, fork of KHTML	-	WebKitGTKWebKit, fork of KHTML	WKWebKitWebKit, fork of KHTML	Edge WebView2Blink, fork of WebKit, fork of KHTML

File manager	Dolphin	GNOME Files (Nautilus)	Thunar	Cajafork of Nautilus	Nemofork of Nautilus	PCManFM-Qt	Nemo (usually)fork of Nautilus	Finder	File Explorer
Archive manager	Ark	File Roller	Xarchiver	Engrampafork of File Roller	-	-	-	Archive Utility	File Explorer
Document/PDF viewer	Okular	Papers, Evince	-	Atrilfork of Evince	xreaderfork of Atril	qpdfview	-	Preview	Edge
Image viewer & management	Gwenview, digiKam, ...	eogEye of GNOME, Loupe, ...	Ristretto	Eye of MATEfork of eog (Eye of GNOME)	xviewerfork of eog (Eye of GNOME), pixfork of gThumb	LXImage	-	Preview, macOS Photos	Windows Photos
Image editing	Krita, ShowFoto	GIMP	-	-	-	-	-	macOS Photos	Paint
Text editor	Kate, KWrite	GNOME Text Editor, gedit	Mousepad	Plumafork of gedit	xedfork of Pluma	Featherpad	-	TextEdit	Notepad, WordPad
Media player	Dragon, Kaffeine, ...	GNOME Videos (Totem)	Parole	-	xplayerfork of Totem	-	-	Quicktime Player	Windows Media Player
Music library	Elisa, Strawberry, ...	Decibels, GNOME Music, ...	Xfmpc	-	-	-	-	Apple Music	Windows Media Player
Web browser	Falkon	GNOME Web (Epiphany)	Midori	-	-	-	-	Safari	Edge
Email client	KMail, Trojita	Geary, Evolution	-	-	-	-	-	macOS Mail	Outlook for Windows
Calendar	KOrganizer	GNOME Calendar	Orage	-	-	-	-	macOS Calendar	Outlook for Windows


General features
Display server support	X11 + Wayland	X11 + Wayland	X11	X11	X11	X11 + Wayland	X11	Quartz Compositor	Desktop Window Manager
Fractional scaling (for HiDPI monitors)	Yes	Experimental	Yes	No	Yes	No	Yes	Yes	Yes
HDR (high-dynamic range) support	Yes	Yes	No	No	No	No	No	Yes	Yes
VRR (variable refresh rate) support	Yes	Experimental	No	No	No	No	No	Yes	Yes
Display colour profiles	Yes	Yes	No	No	No	No	No	Yes	Yes
Can draw generic window decorations ("server-side decorations")Meaning the desktop environment will draw generic window decorations (such as minimize, maximize and close buttons) for applications that don't want to draw their own custom window decorations. In the Linux world, this is usually known as "server-side decorations" (SSD) (drawn by window manager) as opposed to "client-side decorations" (CSD) (drawn by app, hence apps will all have different looks for the title bars and window buttons).	Yes	X11: Yes; Wayland: No	Yes	Yes	Yes	Yes	Yes	YesMacOS technically doesn't have server-side but client-side decorations that are "injected" into the app by default. As they are added automatically by the OS they are essentially the same as server-side decorations same from a developer and user perspective; apps don't have to draw their own window decorations.	YesWindows technically doesn't have server-side but client-side decorations that are "injected" into the app by default. As they are added automatically by the OS they are essentially the same as server-side decorations same from a developer and user perspective; apps don't have to draw their own window decorations.
Theme support, including 3rd-party themes	Yes	Not out of the boxneed to install gnome-tweaks and gnome-shell-extensions	Yes	Yes	Yes	Yes	Yes	No	No
Scheduled theme switch (e.g. dark theme at night)	No	No	No	No	No	No	No	Yes	No
Night light (reduces blue light)	Yes	Yes	Yes	No	Yes	No	Yes	Yes	Yes
Shake mouse to enlarge and find cursor	Yes	No	No	No	No	No	No	Yes	No
Permission system for apps recording the screen	Yes (on Wayland)implements permission control for privileged Wayland protocols like `screencopy`	Yes (on Wayland)implements permission control for privileged Wayland protocols like `screencopy`	No	No	No	No	No	YesSince macOS Sequoia, the user needs to give explicit permission when an app tries to record the screen	YesPermission settings can be found in Settings -> Privacy & security -> Screenshots & apps .By default all apps can take screenshots.

Panel elements w/o extensions or hidden settings/tweaks
Favourited/pinned apps	in app launcher and panel	in "Activities" dash	in app launcher and panel	in app launcher and panel	in app launcher and panel	in panel	in panel	in dock	in start menu and panel
Panel location changeable (e.g. bottom, top)	Yes (all four sides)	No	Yes (all four sides)	Yes (all four sides)	Yes (all four sides)	Yes (all four sides)	Yes (all four sides)	No, but can move dock	No
Panel auto-hide function	Yes	No	Yes	Yes	Yes	Yes	Yes	No, but can auto-hide dock	Yes
Clock/volume/battery/network status/keyboard layout	Yes (all)	Yes (all)	Yes (all)	Yes (all)	Yes (all)	Yes (all)	Yes (all)	Yes (all)	Yes (all)
Notification list (e.g. new e-mail, updates available)	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Icons for background apps (e.g. cloud sync, messenger)	Yes	LimitedBackground app indicators and sticky notifications, but no classic tray icons.	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Toggle between local (in-window) menus or global menubar	Yes (default: local)	No (always local)	Yes (default: local)	Yes (default: local)	No (always local)	No (always local)	Yes (default: local)	No (always global)	No (always local)
Quickly uninstall apps from app launcher (e.g. right-click)	Yes	No	No	No	No	No	No	Yes	Yes

Window management
Taskbar/dock: toggle between showing windows or apps	Yes	No (shows neither)dash (in "Activities" screen) shows running apps, but panel doesn't show running apps or open windows	Yes	Yes	Yes	Yes	Yes	No (only shows apps)	Yes
Maximize window (without hiding panel/dock/taskbar)	Yes	Yes (right-click)	Yes	Yes	Yes	Yes	Yes	keyboard shortcut only	Yes
Fullscreen (hides panel and other element)	Yes	keyboard shortcut only	Yes (right-click only)	keyboard shortcut only	keyboard shortcut only	keyboard shortcut only	keyboard shortcut only	Yes	No
Minimize	Yes	Yes (right-click)	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Show desktop (minimize all windows)	Yes	keyboard shortcut only	Yes	Yes	Yes	Yes	Yes	keyboard shortcut onlyor trackpad gesture	Yes
Keep window on top	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	No	No
Move to other workspace/show window on all workspacesworkspace = virtual desktop	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Yes (right-click)	Drag & drop / No	Only in Task View
Tile windows by moving them to the screen edge ("Snapping")	Yes (½ or ¼ screen)	Yes (½ screen only)	Yes (½ or ¼ screen)	Yes (½ or ¼ screen)	Yes (½ or ¼ screen)	No	Yes (½ screen only)	Yes (½ or ¼ screen)	Yes (½, ⅓ or ¼ screen)
Move/resize windows using Alt (or Meta) + Left/Right Click	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	No/No	No/No	No/No
Show overview of all windows and workspaces	Yes	Yes	Yes	No	Yes	No	No	Yes	Yes
Virtual desktop cube	Yes	No	No	No	No	No	No	No	No

File manager	Dolphin	GNOME Files (Nautilus)	Thunar	Caja	Nemo	PCManFM-Qt	Nemo (usually)	Finder	File Explorer
Icon/column/tree view	Yes/Yes/Yes	Yes/Yes/Yes	Yes/Yes/in side panel	Yes/Yes/in side panel	Yes/Yes/in side panel	Yes/Yes/in side panel	Yes/Yes/in side panel	Yes/Yes/No	Yes/Yes/in side panel
Tabs or split-pane view	Yes/Yes	Yes/No	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/No	Yesexperimental/No
Toggle to show/hide hidden files	Yes	Yes	Yes	Yes	Yes	Yes	Yes	keyboard shortcut only	Yes
Sort by: name/type/size/date	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes	Yes/Yes/Yes/Yes
Thumbnail support in file manager and file pickeropen/save dialogue	Yes/Yes	Yes/YesSince GNOME 47, Nautilus can be used for the file picker, see here. Previously (since 2023), thumbnails only worked if the folder was opened previously in the file manager; if new files have been added in the meantime the folder needs to be reloaded in the file manager to generate thumbnails. Before that there was a request to implement thumbnails that had been open since early 2004, so for over 18.5 years (!)	Yes/No	Yes/No	Yes/No	Yes/Yes	Yes/No	Yes/Yes	Yes/Yes
Type-ahead find in active folder	Yes	No	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Filter files in active folder	Yes	Not reallyYou can change the "Search in Subfolders" setting to "Never". This will filter the files in the folder by name, but you lose the recursive search feature.	Not reallyYou can change the "Search in Subfolders" setting to "Never". This will filter the files in the folder by name, but you lose the recursive search feature.	No	No	Yes	No	No	No
Recursive file search	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Undo rename or deletion with Ctrl+Z	Yes	Yes	Yes	Yes	Yes	No	Yes	YesCmd + Z	Yes
Duplicate file options	Keep new/old/rename	Keep new/old/rename	Keep new/old	Keep new/old/rename	Keep new/old/rename	Keep new/old/rename	Keep new/old/rename	Keep new/old/rename	Keep new/old/rename
Create new empy file	Yes	only files from ~/Templates	Yes	Yes	Yes	Yes	Yes	No	Yes
Select multiple files with Ctrl/Shift, and invert selection	Yes/Yes	Yes/keyboard shortcut only	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/Yes	Yes/keyboard shortcut only	Yes/Yes
Edit, copy or paste folder location/path	Yes	Yes	Yes	Yes	Yes	Yes	Yes	keyboard shortcut only	Yes
Go up a level (to parent directory)	Yes	keyboard shortcut only	Yes	Yes	Yes	Yes	Yes	keyboard shortcut only	Yes

Distribution support
Number of supporting active distributions (Distrowatch.com , 04/2024)	66	74	95	54	34	34	14	macOS only	Windows only
Debian	option during installation	pre-selected at installation	option during installation	option during installation	option during installation	option during installation	officially supported
Ubuntu	default in Kubuntu	default desktop (modifiedUbuntu comes with a heavily modified GNOME desktop by default, which is configured to look and behave similar to the previous default desktop Unity)	default in Xubuntu	default in Ubuntu MATE	default in Ubuntu Cinnamon	default in Lubuntu	default in Ubuntu Budgie
Fedora	default in KDE Edition	default Workstation Edition	default in Xfce Spin	default in MATE Spin	default in Cinnamon Spin	default in LXQt Spin	default in Budgie Spin
openSUSE	option during installation	option during installation	option during installation	officially supported	officially supported	officially supported	officially supported
Arch	option during installationin archinstall	option during installationin archinstall	option during installationin archinstall	option during installationin archinstall	option during installationin archinstall	option during installationin archinstall	option during installationin archinstall
FreeBSD	officially supported	officially supported	officially supported	officially supported	officially supported	officially supported	officially supported

Usage share (estimate)
GamingOnLinux.com User Statistics (02/2025)	43.2%	26.4%	6.4%	2.2%	7.9%	0.4%	0.8%
Hardware for Linux Trends (05/2025)	38.2%	34.1%	4.7%	1.9%	9.4%	1.9%	0.3%
Arch (no default desktop) - installations (05/2025)	33.5%	18.5%	11.6%	2.0%	2.9%	2.5%	0.7%

KDE Plasma

GNOME

Xfce

MATE

Cinnamon

LXQt

Budgie

Aqua (macOS)

Windows Shell

General

License

GPL

GPL, LGPL, BSD

GPL, LGPL

GPL

GPL, LGPL

Proprietary

First release

1998

1999

1997

2011

2013

2000

Forked from

GNOME 2

GNOME 3

LXDE & Razor-qt

Corporate and government backing

Blue Systems, Canonical, Google, Qt Group, SUSE 
IBM (Red Hat), Canonical, Google, SUSE, System76 

- 
- 
- 
- 
- 

Apple
Microsoft

Application suite

Legend: KDE app or fork GNOME app or fork uses Qt uses GTK

GUI toolkit

GTK

Cocoa

WinUI

Window manager

KWin

Mutter

Quartz Compositor

Desktop Window Manager

Preferred display manager

SDDM

GDM

LightDM

SDDM

LightDM

macOS login screen

Windows login screen

Embedded HTML engine

File manager

Dolphin

GNOME Files (Nautilus)

Thunar

PCManFM-Qt

Finder

File Explorer

Archive manager

Ark

File Roller

Xarchiver

Archive Utility

File Explorer

Document/PDF viewer

Okular

Papers, Evince

qpdfview

Preview

Edge

Image viewer & management

Gwenview, digiKam, ...

, Loupe, ...

Ristretto

LXImage

Preview, macOS Photos

Windows Photos

Image editing

Krita, ShowFoto

GIMP

macOS Photos

Paint

Text editor

Kate, KWrite

GNOME Text Editor, gedit

Mousepad

Featherpad

TextEdit

Notepad, WordPad

Media player

Dragon, Kaffeine, ...

GNOME Videos (Totem)

Parole

Quicktime Player

Windows Media Player

Music library

Elisa, Strawberry, ...

Decibels, GNOME Music, ...

Xfmpc

Apple Music

Windows Media Player

Web browser

Falkon

GNOME Web (Epiphany)

Midori

Safari

Edge

Email client

KMail, Trojita

Geary, Evolution

macOS Mail

Outlook for Windows

Calendar

KOrganizer

GNOME Calendar

Orage

macOS Calendar

Outlook for Windows

General features

Display server support

X11 + Wayland

X11

X11 + Wayland

X11

Quartz Compositor

Desktop Window Manager

Fractional scaling (for HiDPI monitors)

Yes

Experimental

Yes

HDR (high-dynamic range) support

Yes

VRR (variable refresh rate) support

Yes

Experimental

Yes

Display colour profiles

Yes

X11: Yes; Wayland: No

Yes

Theme support, including 3rd-party themes

Yes

Scheduled theme switch (e.g. dark theme at night)

Yes

Night light (reduces blue light)

Yes

Shake mouse to enlarge and find cursor

Yes

Permission system for apps recording the screen

Panel elements w/o extensions or hidden settings/tweaks

Favourited/pinned apps

in app launcher and panel

in "Activities" dash

in app launcher and panel

in panel

in dock

in start menu and panel

Panel location changeable (e.g. bottom, top)

Yes (all four sides)

No, but can move dock

Panel auto-hide function

Yes

No, but can auto-hide dock

Yes

Clock/volume/battery/network status/keyboard layout

Yes (all)

Notification list (e.g. new e-mail, updates available)

Yes

Icons for background apps (e.g. cloud sync, messenger)

Yes

Toggle between local (in-window) menus or global menubar

Yes (default: local)

No (always local)

Yes (default: local)

No (always local)

Yes (default: local)

No (always global)

No (always local)

Quickly uninstall apps from app launcher (e.g. right-click)

Yes

Window management

Taskbar/dock: toggle between showing windows or apps

Yes

No (only shows apps)

Yes

Maximize window (without hiding panel/dock/taskbar)

Yes

Yes (right-click)

Yes

keyboard shortcut only

Yes

Fullscreen (hides panel and other element)

Yes

keyboard shortcut only

Yes (right-click only)

keyboard shortcut only

Yes

Minimize

Yes

Yes (right-click)

Yes

Show desktop (minimize all windows)

Yes

keyboard shortcut only

Yes

Keep window on top

Yes (right-click)

Drag & drop / No

Only in Task View

Tile windows by moving them to the screen edge ("Snapping")

Yes (½ or ¼ screen)

Yes (½ screen only)

Yes (½ or ¼ screen)

Yes (½ screen only)

Yes (½ or ¼ screen)

Yes (½, ⅓ or ¼ screen)

Move/resize windows using Alt (or Meta) + Left/Right Click

Yes/Yes

No/No

Show overview of all windows and workspaces

Yes

Virtual desktop cube

Yes

File manager

Dolphin

GNOME Files (Nautilus)

Thunar

Caja

Nemo

PCManFM-Qt

Nemo (usually)

Finder

File Explorer

Icon/column/tree view

Yes/Yes/Yes

Yes/Yes/in side panel

Yes/Yes/No

Yes/Yes/in side panel

Tabs or split-pane view

Yes/Yes

Yes/No

Yes/Yes

Yes/No

/No

Toggle to show/hide hidden files

Yes

keyboard shortcut only

Yes

Sort by: name/type/size/date

Yes/Yes/Yes/Yes

Thumbnail support in file manager and

Yes/Yes

Yes/

Yes/No

Yes/Yes

Yes/No

Yes/Yes

Type-ahead find in active folder

Yes

Filter files in active folder

Yes

Recursive file search

Yes

Undo rename or deletion with Ctrl+Z

Yes

Duplicate file options

Keep new/old/rename

Keep new/old

Keep new/old/rename

Create new empy file

Yes

only files from ~/Templates

Yes

Select multiple files with Ctrl/Shift, and invert selection

Yes/Yes

Yes/keyboard shortcut only

Yes/Yes

Yes/keyboard shortcut only

Yes/Yes

Edit, copy or paste folder location/path

Yes

keyboard shortcut only

Yes

Go up a level (to parent directory)

Yes

keyboard shortcut only

Yes

keyboard shortcut only

Yes

Distribution support

Number of supporting active distributions (Distrowatch.com , 04/2024)

macOS only

Windows only

Debian

option during installation

pre-selected at installation

option during installation

officially supported

Ubuntu

default in Kubuntu

default desktop ()

default in Xubuntu

default in Ubuntu MATE

default in Ubuntu Cinnamon

default in Lubuntu

default in Ubuntu Budgie

Fedora

default in KDE Edition

default Workstation Edition

default in Xfce Spin

default in MATE Spin

default in Cinnamon Spin

default in LXQt Spin

default in Budgie Spin

openSUSE

option during installation

officially supported

Arch

FreeBSD

officially supported

Usage share (estimate)

GamingOnLinux.com User Statistics (02/2025)

43.2%

26.4%

6.4%

2.2%

7.9%

0.4%

0.8%

Hardware for Linux Trends (05/2025)

38.2%

34.1%

4.7%

1.9%

9.4%

1.9%

0.3%

Arch (no default desktop) - installations (05/2025)

33.5%

18.5%

11.6%

2.0%

2.9%

2.5%

0.7%

Full list of desktop environments

Legend: major currently used desktop environment, minor desktop, smartphone user interface, ~~discontinued/dead~~

For Unix, Linux, and other Unix-like operating systems

EFL toolkit

Enlightenment
Moksha (Bodhi Linux)
Tizen UI (Tizen OS)

FLTK toolkit

~~Equinox/EDE~~

Flutter toolkit

Pangolin Desktop UI (dahliaOS)

Fyne toolkit

FyneDesk

GNUStep toolkit

~~Etoile~~
GSDE
Nextspace

GTK toolkit

Budgie (Solus)
Cinnamon (Linux Mint)
~~Consort~~
Endless Shell (Endless OS)
GNOME
GNOME Classic
GNOME Flashback
GNOME Shell for Mobile
~~Graphite Desktop~~
~~GPE~~
Hildon (Maemo Leste)
JADE
~~Java Desktop System (Solaris)~~
Manokwari (BlankOn Linux)
MATE
Material Shell
~~Maynard~~
~~Mezzo~~
Kiran Desktop
LXDE
Onyx Desktop (Crystal Linux)
Pantheon (elementaryOS)
Pearl DE (Pearl Linux
Phosh (PureOS)
PIXEL Desktop (Raspberry Pi OS)
Regolith Desktop (Regolith Linux)
~~ROX Desktop~~
Sugar
Unicorn Desktop (Rhino Linux)
UnityX (Ubuntu Unity)
~~Vera~~
XFast
Xfce

Iced toolkit

COSMIC (Pop_OS!)

Motif toolkit

CDE/Common Desktop Environment
~~IRIX Interactive Desktop (IRIX)~~
~~HP VUE (HP-UX)~~
MaXX Interactive Desktop
~~Panorama Desktop~~
~~X.desktop~~

OLIT/Xview toolkit

~~openlook~~
~~Open Windows (Solaris)~~

Qt toolkit (or forks of Qt)

~~airyx Desktop (airyxOS)~~
~~BE::Shell~~
Cutefish
Deepin Desktop (Deepin Linux)
Draco DE
~~Elokab~~
Fly Desktop (Astra Linux)
Glacier UX (Nemo Mobile)
~~Hawaii~~
hello Desktop (helloSystem)
~~Innova~~
Jing Desktop (JingOS)
Katana DE (fork of KDE Plasma 4)
KDE Liquidshell
KDE Plasma
KDE Plasma Mobile
~~Kuartet~~
Liri Shell (Liri OS)
Lomiri (Ubuntu Touch)
Lumina
Luna Next (Open WebOS)
LWQt
LXQt
Maui Shell (convergent, for desktop and mobile)
~~MoonlightDE~~
NX Desktop (Nitrux)
~~OPIE~~
Orbitiny Desktop
~~Papyros~~
~~Razor-qt~~
Sailfish UI (Sailfish OS)
thedesk
~~theShell~~
Trinity Desktop
UKUI (Ubuntu Kylin)
~~Unity 2D~~

Xlib toolkit

Sxmo
~~UDE/Unix DE~~

Other, for X Server or Wayland

Fvwm-Crystal
~~Fvwm-Nightshade~~
Magma (ravynOS()
nsCDE
~~Project Looking Glass~~
PsychDOS
Stacking and compositing stand-alone window managers: 2bwm, 9wm, AfterStep, amiwm, berry, Blackbox, Compiz, CTWM, cwm, eggwm, EMWM, evilwm, Fluxbox, Flwm, Fvwm, Goomwwm, IceWM, jbwm, JWM, Karmen, lwm, Matchbox, MWM, olwm, Openbox, pawm, PekWM, Qvwm, Sawfish, Scwm, sowm, swm, TinyWM, twm, tvtwm, ukwm, UWM, vwm, vtwm, Wind, WindowMaker, WindowLab, Wio, wm2
Tiling and dynamic stand-alone window managers: Alopex, awesome, Bspwm, dwm, echinus, EXWM, FrankenWM, Herbstluftwm, i3, Ion, Larswm, NotionWM, Qtile, Ratpoison, spectrwm, StumpWM, subtle, Sway, Velox, Wingo, WMFS2, wmii, Worm, xmonad

Other, not using X Server oder Wayland

various Android interfaces, incl. for Android forks
Aqua (macOS)
Aura Shell (ChromeOS)
~~Bada GUI (Bada OS)~~
Durden
egmde
Gala (KaiOS/FirefoxOS)
~~NeXTSTEP Desktop~~
Orbital (Redox OS)
~~Photon (QNX)~~
rio (Plan 9 and forks)
Screen (QNX)
SerenityOS GUI (SerenityOS)
skiftOS GUI (skiftOS)
Springboard (iOS/iPadOS)
wm (Inferno)
XaAES (FreeMiNT)
Yutani (ToaruOS)

For Windows and Windows-like operating systems

ReactOS Explorer (ReactOS)
Windows Shell (Microsoft Windows)

Alternative, third-party desktops for Windows: BB4Win, BBLean, Cairo Desktop, Emerge Desktop, GeoShell, Litestep, OpenShell, Program Manager II, Seelen-UI, SharpEnvironment, Talisman Desktop, ...

Workspace Shell (ArcaOS)

For AmigaOS and Amiga-like operating systems

Workbench (AmigaOS)
Ambient (MorphOS)
Magellan (Icaros)
Wanderer (AROS)

For other still actively developed operating systems

Bluebottle GUI (Bluebottle OS)
ChrysaLisp GUI (ChrysaLisp OS)
DawnOS GUI (DawnOS)
DexOS GUI (DexOS)
DECWindows (OpenVMS)
Essence GUI (Essence OS)
Ghost GUI (Ghost OS)
HelenOS GUI (HelenOS)
KolibriOS GUI (KolibriOS)
MenuetOS GUI (MenuetOS)
Mezzano GUI (Mezzano OS)
MonaOS GUI (MonaOS)
OpenTracker (Haiku)
PhantomOS GUI (PhantomOS)
Pinboard (RISC OS)
Sculpt (Genode)
Solar OS GUI (Solar OS)
SymbOS GUI (SymbOS)
Visopsys GUI (Visopsys)

Click here to show my review of 15 Linux desktop environments, with screenshots and comparison of RAM use (from 2021, will not be updated anymore)

RAM Use

Below is a graph showing the RAM use in excess of the 261 MB used by the base system (without GDM3 or X.Org running).

This is based on 3 test runs:

Run 1:

separate Ubuntu distributions/"flavours" in separate VMs (official versions: Kubuntu, Xubuntu, Lubuntu, Ubuntu Budgie, Ubuntu MATE, Ubuntu Kylin, elementary OS; inofficial versions: Unity Remix, Lumina Remix, Cinnamon Remix, Ubuntu DDE; Ubuntu Net Install with manual installation of Gnome-Shell, TDE, Enlightenment, and CDE)
RAM measured with screenfetch

Run 2:

all DEs installed in same system with different user accounts (1 DE = 1 user) to keep settings separate
vanilla desktop settings (e.g. standard Xfce-Session instead of Xubuntu's version)
RAM measured with screenfetch
each DE was measured after logging in and out of another DE (this lead to higher RAM use on average, possibly because some processes and services were not killed after logging out the previous user)

Run 3:

all DEs installed in same system with different user accounts (1 DE = 1 user) to keep settings separate
vanilla desktops (e.g. standard Xfce-Session instead of Xubuntu's version)
RAM measured with top
system restart between each uptime

Results:

Enlightenment: 70 MB. (best performance: run 3, Ubuntu 20.04 + Enlightenment from Ubuntu repository)
Lumina: 93 MB. (best performance: run 1, Ubuntu 20.04 Lumina Remix)
Trinity: 185 MB. (best performance: run 1, Ubuntu 20.04 + Trinity from developer's PPA)
LXQt: 243 MB. (best performance: run 1, Lubuntu 20.04)
Pantheon: 302 MB. (best performance: run 1, elementary OS Hera based on Ubuntu 18.04)
Unity: 335 MB. (best performance: run 3, Ubuntu 20.04 + Unity from Ubuntu repository)
Budgie: 336 MB. (best performance: run 3, Ubuntu 20.04 + Budgie from Ubuntu repository)
KDE Plasma: 347 MB. (best performance: run 1, Kubuntu 20.04)
Cinnamon: 348 MB. (best performance: run 3, Ubuntu 20.04 + Cinnamon from Ubuntu repository)
MATE: 376 MB. (best performance: run 3, Ubuntu 20.04 + MATE from Ubuntu repository)
Xfce: 394 MB. (best performance: run 1, Xubuntu 20.04)
GNOME: 408 MB. (best performance: run 3, Ubuntu 20.04 + Gnome-Shell from Ubuntu repository)
CDE: 419 MB. (best performance: run 1, Ubuntu 20.04 + CDE from SparkyLinux repository)
UKUI: 438 MB. (best performance: run 3, Ubuntu 20.04 + UKUI from Ubuntu repository)
Deepin: 490 MB. (best performance: run 3, Ubuntu 20.04 + Deepin from UbuntuDDE PPA)

Having a closer look

Budgie

Desktop environment originally created for Solus but also available for other distributions
Based on GNOME 3, doesn't come with own applications but uses GNOME apps
More traditional and convenient workflow than GNOME, with dock showing opened apps
High RAM usage, like GNOME
Elegant design
Conclusion: average

Features: 3/5
Polish: 4/5
Resource usage: 2/5

Common Desktop Environment (CDE)

The oldest desktop environment tested, created in 1993 for commercial Unix systems, later ported to Linux, open source since 2012
Uses the Motif toolkit, unlike most other desktops which use either GTK or Qt
Somewhat inconvenient workflow (no window list, no window snapping/tiling etc), some quirky ideas (from today's perspective), such as minimizing windows into a desktop icon
Medium RAM usage (surprising as this desktop is straight from the 90s - maybe it's not optimized to run on Ubuntu yet)
Very classic design, unique feel
Not quite recommendable as a daily driver, but if you like the look and feel there is nsCDE
Conclusion: not recommended

Features: 1/5
Polish: 2/5
Resource usage: 1/5

Cinnamon

A more traditional interface alternative to GNOME 3, from which Cinnamon was forked
Created by the Linux Mint team and their flagship desktop environment
Uses mostly GNOME/MATE applications
Traditional interface with start menu, taskbar and tray
Quite customizable, definitely moreso than GNOME
Better file manager than GNOME's "Files"
Average design, neither very modern nor very old fashioned (the above screenshot is from Ubuntu Cinnamon Remix and uses an ugly orange theme - Linux Mint looks better)
High RAM usage, like GNOME 3, is the main drawback
Conclusion: recommended

Features: 4/5
Polish: 4/5
Resource usage: 2/5

Deepin Desktop Environment (DDE)

Created for Deepin Linux, a Chinese Linux distribution
Based on DTK (fork of Qt), comes with its own set of applications
Elegant, modern design
Easy to use and pretty, main downside is that you have to trust the Chinese developers to not have put any hidden CCP spyware in
Medium-high RAM usage
Conclusion: average

Features: 3/5
Polish: 5/5
Resource usage: 1/5

Enlightenment

Started as a window manager in the 1990s, now it has slowly grown into a small, lightweight desktop environment, with its own set of core applications
Uses it's own widget toolkit, which is also used in Samsung's Tizen operating system
Customizable and powerful window manager, rather basic file manager
Very lightweight compared to all other desktop environments, however not so much when compared to stand-alone window managers (e.g. JWM, IceWM)
Conclusion: average

Features: 2/5
Polish: 3/5
Resource usage: 5/5

GNOME

Default for virtually all corporate distributions (e.g. Fedora/RHEL, Ubuntu, Solaris), and generally available for most distributions
Backed by IBM; many of GNOME's core developers are IBM (Red Hat) employees. Thanks to this, GNOME feels quite polished, without obvious bugs or papercuts.
Back in the 90s, GNOME was founded because KDE used the (then) proprietary Qt toolkit, and GNOME was hence built on the completely free GTK toolkit created for GIMP. Shortly after, Qt became free software as well, but GNOME development continued. The KDE-GNOME schism remains until today.
Together with KDE, GNOME is the only desktop environment will a full set of applications
GNOME 3 was a very controversial release, with a completely new UI and workflow, which was mainly targeted at tablets and touchscreen devices, because everyone in 2011 thought PCs would die and everyone would use tablets in the future (see also: Windows 8). While Windows went back to a more traditional interface in 2015 (Windows 10), GNOME has retained its idiosyncratic workflow.
There is no taskbar or dock indicating running applications or open windows. In fact, in order to switch windows or open a new application, one needs click in the top left corner or use the Super key to access the "Activities" screen, a fullscreen overlay showing thumbnails of all open windows as well as a button to show the list of installed programs. This hassle to switch windows encourages users to display only one app at a time (just how you would on a mobile device running iOS/Android), hence also the lack of minimize and maximize buttons.
Nautilus, the file manager, lacks some very elementary features, such as type-ahead find or thumbnails in the file picker.
GNOME is probably the least customizable desktop, there are very few available settings, no theme API etc.
High RAM usage compared to KDE Plasma or Xfce
Average design, neither very modern nor very old-fashioned
Regarding the GNOME developers:

The GNOME developers have shown a disregard for user feedback, for example, it has been over 15 years and the GNOME filepicker still does not support thumbnails, or as another example, type-ahead file selection in the GNOME file manager was removed and will not come back as the GNOME developers prefer users to follow the GNOME way instead of GNOME following the user's workflow preferences.
GNOME does not integrate well with other desktops, for example it doesn't support tray icons or server-side window buttons and has asked software developers to change their applications to follow the GNOME way, even if this would break features on other desktops. For this reason, the developer of well-known media player MPV has even accused the GNOME developers of deliberately sabotaging the Linux desktop.
The GNOME Code of Conduct takes a stand against racism, sexism, transphobia etc, but on the other hand explicitly tolerate anti-white racism, misandry etc.
The GNOME foundation signed the open letter against Richard M. Stallman and the Free Software Foundation in 2021.

Conclusion: not recommended

Features: 2/5
Polish: 5/5
Resource usage: 1/5

KDE Plasma

The second-oldest full desktop environment for Linux (after Xfce)
Uses the Qt toolkit
Together with GNOME, it is the only desktop with a full set of applications
Very customizable. The most features and customization options of all desktop environments.
KDE Plasma can do anything you like, but due to the infinite amount of options and settings there is a higher chance of encountering bugs if you stray too far from the standard settings. (Although newer versions have far fewer bugs than Plasma used to have in the past.)
Dolphin is the best file manager among all desktops. It even supports thumbnails in the file picker!
Low to medium RAM usage, in my test it was even lower than Xfce's.
The design was very modern when it first came out (no wonder Windows copied them), but is starting to feel a bit dated. Fortunately KDE can be themed any way you like.
Overall the best desktop environment, with the most features, most customization options, and one of the lowest RAM usages.
Most Linux distributions as well as BSD offer KDE Plasma. However, none of the major distributions commits to KDE Plasma as the default desktop. Historically KDE-focused distributions have either disappeared (Mandriva, Mepis) or have become desktop-agnostic (OpenSuse).
Conclusion: recommended

Features: 5/5
Polish: 4/5
Resource usage: 2/5

Lumina

Originally developed for TrueOS (a FreeBSD fork), then for Linux-based distributino "Project Trident" which has now also been discontinued.
Lightweight Qt-based desktop developed from scratch
Few own applications, and they are not that great either.
Default design is not very pretty
The main merit is the low resource usage
Few distributions offer Lumina
Conclusion: not recommended

Features: 2/5
Polish: 2/5
Resource usage: 5/5

LXQt

Lightweight Qt-based desktop environment
Successor of LXDE (GTK-based) and Razor-qt
Few own applications
Traditional interface with panel and the usual customization options
Low RAM usage, interesting alternative to the more Xfce or MATE
Conclusion: recommended

Features: 4/5
Polish: 4/5
Resource usage: 3/5

MATE

Continuation of GNOME 2
Easy to use, flexible interface, somewhat outdated design
Medium RAM usage
Uses its own set of GNOME-based applications from the GNOME 2 stack
Available for most distributions, as well as all BSDs and Illumos
Conclusion: recommended

Features: 4/5
Polish: 4/5
Resource usage: 2/5

Pantheon

Created for elementary OS, but also available for other distributions
Based on GNOME 3, but comes with its own set of core applications developed from scratch
Elegant, simple design, although clearly inspired by macOS
Not very customizability, little features that set it apart
Surprisingly moderate RAM usage
Conclusion: average

Features: 3/5
Polish: 5/5
Resource usage: 2/5

Trinity Desktop Environment (TDE)

Continuation of KDE 3.5
Comes with a full set of applications inherited from KDE 3.5
Uses TQt, a fork of Qt 3
Low RAM usage, making it a good option for old computers
Like KDE, it is full of features and can be completely customized
Outdated default design, but can be themed
Small developer team
"Finished product", don't expect any major features added in updates
Few distributions offer TDE, however the TDE developers offer binaries for all major distributions. A notable distribution with TDE support is Q4OS.
Conclusion: recommended

Features: 5/5
Polish: 3/5
Resource usage: 4/5

UKUI (Ubuntu Kylin User Interface)

Created for Ubuntu Kylin, the Ubuntu variant for the Chinese market, and only available for few other distributions
Originally based on MATE (GNOME 2), however recently switched to Qt and KWin (KDE's window manager).
Very few UKUI applications, mostly employs MATE applications.
Elegant design
Classic layout, the panel clearly imitated Windows 10
Conclusion: average

Features: 3/5
Polish: 4/5
Resource usage: 1/5

UnityX

Unity was created by Canonical for Ubuntu, originally as an interface for netbooks, then used as the default Ubuntu desktop from 2011 to 2017.
Canonical has since stopped further development. Their last stable version, Unity 7, is now a mature product, polished and without major bugs, while Unity 8 (based on Qt, for both mobile devices and desktops) was still very experimental when Canonical stopped development. The development of Unity 7 continues as UnityX, and Unity 8 for Linux phones has been renamed to Lomiri. Both are developed by the community now.
Uses a global menu by default, similar to macOS
Easy to use and the most important customization options are there
No own applications, uses GNOME apps
Default design is becoming a bit outdated
Only really available for Ubuntu, no other distribution has bothered to support Unity.
Conclusion: average

Features: 3/5
Polish: 5/5
Resource usage: 2/5

Xfce

The oldest desktop environment developed for Linux, slightly preceding KDE and GNOME.
Traditionally the lightweight alternative to GNOME and KDE Plasma
Mature product with relatively slow development pace
However, recently KDE Plasma has become just as lightweight (in terms of RAM use) as Xfce, and some new desktops like LXQt are even more lightweight than those two
Comes with a small set of Xfce applications
Customizable and easy to use
Traditional workflow
Default design looks outdated, but can be themed
Conclusion: recommended

Features: 4/5
Polish: 5/5
Resource usage: 2/5