Unity-Headers Concept: using server-side hearderbars to create a consistent, customizable and space-saving UI, for most applications.

Customized Unity-Headers behavior: KDE’s Okular app, with a headerbar and a HUD menu-search interface (mockup, HUD is from another app). The user can hide the toolbar from within the application. The headerbar is just serve-side decoration.
Proposed default Unity-Headers behavior a la Unity LIM: Evolution window with a (flexible) full menu bar and an empty menu-item drawer. (HUD is also standard)
Unity-Headers solution for color mismatch. (Sublime text)

Why headerbars and HUD?

Why server-side?

Gnome Builder HUD+Headerbar preview.

Unifying window decorations for all apps.

Headerbars in KWin’s DWD proposal.
Headerbars in Gnome CSD decorations.

The Problem

Does this look like a consistent UI to you?

The “Unity-Headers” Solution: Windows.

Unity LIM
KWin LIM
Evoltion.
Evolution decorated with Unity-Headers (example 1)
Evolution (Example 2)
Sublime Text
Sublime inside Unity-Headers
Here is Okular with Unity-Headers:
Is this Evince?
Firefox CSD
Firefox dark, no CSD. Looks terrible.
Firefox Unity-Headers, the window buttons would be white obviously, this is just a mockup.
Visual Studio Code CSD

Unity-Headers: What about titlebar actions?

The Unity-Headers solution part 2: the HUD

TL;DR: The Result

Interested?

Survey results: