Gnome: Remove title bar when maximized

Hide the useless titlebar when a window/application is maximized:[src]

No more title bar

  1. Edit metacity-theme-3.xml:
    sudo nano /usr/share/themes/Adwaita/metacity-1/metacity-theme-3.xml
  2. Press CTRL + w and type frame and press ENTER.
  3. Your file may differ but see that the found section in your file matches the following snippet with regard to the highlighted values:
    <frame_geometry name="max" has_title="false" title_scale="medium" parent="normal" rounded_top_left="false" rounded_top_right="false">
         <distance name="left_width" value="0" />
         <distance name="right_width" value="0" />
         <distance name="left_titlebar_edge" value="0"/>
         <distance name="right_titlebar_edge" value="0"/>
         <distance name="title_vertical_pad" value="0"/>
         <border name="title_border" left="0" right="0" top="0" bottom="0"/>
         <border name="button_border" left="0" right="0" top="0" bottom="0"/>
         <distance name="bottom_height" value="0" />
    </frame_geometry>
    
    • Ubuntu: Press ALT + F2,
      Fedora/Korora: Press ALT + F2 and enter r, press ENTER.

XFCE HiDPI fix `everything too small`

Mate Desktop can do that right out of the box and features better UI/UX. Spare yourself the pain of XFCE - we gave up an used the HiDPI ready Ubuntu Mate.

What you can achieve

XFCE: More or less fixed HiDPI problems

XFCE in general

  1. HiDPI theme: http://opendesktop.org/content/show.php/Pupi+%28Xfce+High+DPI+%2B+Retina+Theme%29?content=165525

Firefox

  1. about:config: layout.css.devPixelsPerPx
  2. Adjust default zoom level

Thunderbird

  1. about:config: layout.css.devPixelsPerPx

Ressources
- HiDPI: Xfce (wiki.archlinux.org)