Alternatives
If you use a Linux desktop other than GNOME, for example KDE Plasma or XFCE, then you cannot run GNOME extensions. (At least, out of the box.) The same holds true if you use a tiling window manager (Hyprland, Awesome, etc.).
If, for whatever reason, you cannot run the Draw On Gnome extension, here are some FOSS Linux alternatives:
gromit-mpx
This is a simpler program but it can run on any *nix-based system.
My Goto Backup
This is my backup drawing program in case Draw On Gnome fails.
Wayscriber
Designed for modern Wayland sessions, not X11.
ScreenPen
Another good alternative. This displays a clickable palette.
Spectacle (screenshot annotator in KDE)
This is for taking screenshots which can then be annotated in the Spectacle program. Another great tool!
Note
If you are interested in annotations of screenshots moreso than annotations of the live screen, then you might also like Flameshot and Ksnip.
Xournal++
More of a note taking app.
OpenBoard
This is a whiteboarding solution.
Drawing
This is a Flatpak install. Written in Python, can work on any Linux distro or GUI.
DrawPen
As of 2026, this is a new development for Linux and other OSes. It has some real promise!
Tip
And for those of you that have to use Windows sometimes, check out gInk - open source and simple to use. Also ZoomIt, which is part of PowerToys.