I'm not sure you're the best person to address my comments too, and I'm
sure you've heard people say things like this a number of times before,
but I saw this in one of your Planet Mozilla posts recently, and I
couldn't resist commenting:

	"Discussion on Linux theme defaults:
		Outcome: No matter what defaults we choose to ship,
		we’ll need to be able to draw in the title bar. Faaborg
		will follow up on this, and make sure bugs are filed."

It would be a great step backward in desktop integration
========================================================

Since Firefox and Seamonkey before it have always been implemented in
XUL instead of GTK+ (and Netscape 4 in Motif before that), they have
always had difficulty in blending with the Linux desktop. Over the
years, lots of people have put in lots of hard work to make Firefox for
Linux look better and work more like an native application, with the
result that Firefox 3.0 was the best-integrated, sexiest-looking
Firefox ever (3.5 and 3.6 of course inherited 3.0's success).

Currently, Firefox's interactions with the title-bar are exactly those
of a native application, and any alternative system is doomed to be
a backward step.

It would be a waste of engineering resources
============================================

From screenshots I've seen, it seems that fitting into the native
Windows Vista look and feel requires applications to decorate their
titlebars with widgets, and Microsoft gives application authors the
tools they need to do so. Fair enough! 

I'm told that Mac OS X doesn't make it easy for applications to draw
their own titlebars, but it doesn't make it particularly difficult
either. The Mac appearance is so consistent that hard-coding the
custom appearance is probably a reasonable engineering trade-off - only
a little extra effort gains much flexibility. Fair enough!

As I'm sure you're well aware, the Linux environment is totally
designed around the notion that applications will stay nicely inside
their windows, and the system will be responsible for drawing a
title-bar (if any). You can create your own custom title-bar that is
totally different from the system settings (as Chrome and XMMS do,
sticking out like sore thumbs), or guess what the system settings might
be and try and replicate them on your own (with all the false-positives
that guessing implies, and the uncanny-valley frustration that comes
from Firefox not implementing things quite the same way as the
underlying OS does). If you had to choose between implementing a
native-titlebar mode, versus implementing a native titlebar mode *and*
implementing a custom titlebar mode that will take much effort and
necessarily produce inferior results, adding a custom titlebar doesn't
make any sense.

(In particular, I'm worried that the engineering concerns will result
in the two modes of Firefox.next being "custom titlebar with widget
sprinkles" and "custom titlebar that awkwardly impersonates the native
titlebar", in much the same way that Firefox can use custom-themed XUL
widgets or GTK+-themed XUL widgets, but not native GTK+.)

There is a precedent for usability over branding
================================================

When Firefox 3.0 came out, it featured a custom "keyhole" shape for the
back and forward buttons on Windows (where there's little
standardisation on application look and feel) and Mac (where there's
rigid standardisation on application look and feel, but no general
precedent for browser navigation buttons). However, Linux *does* have
firm standards for how applications should present back and forward
buttons, and Firefox wisely chose to conform to user expectations
rather than be gratuitously different.

Likewise, there's precedent or even expectation for apps on Windows and
Mac OS to manipulate their titlebars, but not on Linux - for the same
reasons that Firefox on Linux does not have keyhole back/forward
buttons (not just a preference defaulting to off, it's not even
implemented), Firefox on Linux should not waste effort on implementing
custom titlebars.

Conclusion
==========

I'd like to think I'm not against change, and many of the changes
proposed for Firefox 3.7 and 4.0 I find promising, or at least
interesting enough to try out before forming an opinion on them.
However, I feel this widgets-on-the-titlebar thing is just a bad idea -
breaking platform look-and-feel conventions, breaking my mental model
as a user, and generally overly difficult considering the number of
possible desktop environments, possible window managers per
environment, and themes per window manager in the Linux platform. To
misquote Arthur C. Clarke, from the novel 2001:

	ALL THESE WIDGETS ARE YOURS EXCEPT THE TITLEBAR. ATTEMPT NO
	RENDERING THERE.