Unity-2D with XFWM4

[quequotion]

How to get Unity-2D to work with xfwm4:

sudo apt-get install xfwm4

You don't need to install the entire xfce/xubuntu desktop.

gksu gedit /usr/share/gnome-session/sessions/ubuntu-2d.session /usr/share/applications/xfwm4.desktop

In ubuntu-2d.session replace:

DefaultProvider-windowmanager=metacity

with:

DefaultProvider-windowmanager=xfwm4

In xfwm4.desktop (which should be a new, empty file):

[Desktop Entry]
Type=Application
Name=Xfwm4
Exec=xfwm4
NoDisplay=true
# name of loadable control center module
X-GNOME-WMSettingsModule=xfwm4
# name we put on the WM spec check window
X-GNOME-WMName=Xfwm4
# back compat only 
X-GnomeWMSettingsLibrary=xfwm4
X-GNOME-Bugzilla-Bugzilla=GNOME
X-GNOME-Bugzilla-Product=xfwm4
X-GNOME-Bugzilla-Component=general
X-GNOME-Autostart-Phase=WindowManager
X-GNOME-Provides=windowmanager
X-GNOME-Autostart-Notify=true
X-Ubuntu-Gettext-Domain=xfwm4

There may be some better options for the .desktop file. Particularly I couldn't find any hints about what X-GNOME-WMSettingsModule should be.

You can modify the xfwm4 configuration with: xfwm4-settings, xfwm4-tweaks-settings, and xfwm4-workspace-settings. For some reason, these applications will not show up in the menu (they should be in the menu as "xfce settings" etc).

Attached screenshot shows unity-2d panel, nautilus, and gome-terminal in xfwm with composting (activate in xfwm-tweaks-settings)

[quequotion]

Of course, xfwm4 is not designed for unity.

There are a few rough edges, like window decorations don't blend into the panel on maximize and the panel sometimes has a border like an ordinary window. The Smallscreen theme makes these relatively painless.

Here's the screenshot I mentioned before.