AppIndicators StatusNotifierItem

Regarding system tray icons, KDE and Ubuntu/Unity have reached by 2014 a consensus in the StatusNotifierItem specification, thus departing from the previous standard ICCCM/EWMH. GNOME didn't adhere to this proposal.

StatusNotifierItem is an attempt to homogenize tray icon behavior by drastically limiting their possibilities (see #130). I suspect these limitations also result from the perspective of merging desktop and mobile.

Now developers are facing the divergence between EWMH and StatusNotifierItem across desktop environments or window managers. As detecting and supporting all environments (basically Unity, KDE, others) would be costly, some applications (google-chrome, redshift, firetray) have chosen to leverage the libappindicator library which works for both Unity and KDE.

I wish to say to unhappy AppIndicator/KSNI users, that they should turn to their respective environments and push for making the StatusNotifierItem specification evolve further.