It looks like you're interested in using KWin on an Ubuntu system with the X11 window system. KWin is the window manager for KDE Plasma. Here's how you can install and use it:
1. **Install KDE Plasma and KWin:**
Open a terminal and run the following commands:
```bash
sudo apt update
sudo apt install kde-plasma-desktop
```
2. **Switch to KWin:**
If you are already using another desktop environment, you can switch to KDE Plasma by logging out of your current session. On the login screen, select the KDE Plasma session before logging back in.
3. **Ensure KWin is running with X11:**
By default, KDE Plasma should use KWin with X11. You can check which window system is in use by running:
```bash
echo $XDG_SESSION_TYPE
```
This should return `x11`.
If you encounter any issues or need further customization, feel free to ask!
