KWin is the window manager for the KDE Plasma desktop environment, and it can be used on Ubuntu. If you want to install the KDE Plasma desktop along with KWin on Ubuntu, you can do so by running the following commands in the terminal:
1. Update your package list:
```bash
sudo apt update
```
2. Install the KDE Plasma desktop environment:
```bash
sudo apt install kde-plasma-desktop
```
3. Once the installation is complete, you can log out of your current session. On the login screen, you should be able to select KDE Plasma as your desktop environment.
4. Log in with KDE Plasma selected, and KWin will be your window manager.
If you have any specific configurations or issues with KWin on Ubuntu, feel free to ask!
