A lingering bug is bug 757262, probably caused by a significant change in plugin architecture in bug 90268. Let me reiterate that plugins are still not supported, and even 10.5 is having some serious problems with plugin architecture that will probably cause our deprecated plugin support to stop working completely after 10.5 support is removed from Firefox. Nevertheless, if you are bitten by this bug (i.e., the plugin you enabled "against medical advice" fails to shut down when a tab is closed), you are encouraged to follow up in that bug. Don't report it here. Mozilla has decided not to respin since the proposed fix is speculative and no one has proven it works because the manifestation is maddeningly uneven.
This version also fixes the last of the graphical glitches with Azure (mostly issues with CTGradient), puts WebM back to single threaded (not ported to stable either), and fixes the endian problem with WOFF fonts. Smooth scrolling is disabled by default, only enabled for those who previously had it enabled; that's the only new difference between Fx13 and us. Remember, the change in how graphics are painted will affect how the browser reportedly acts, but does appear to be an overall win. We can expect the graphics stack and painting operations to change further as Mozilla tries to wring more efficiency out; most of this is likely to land in the Fx15/16 timeframe.
Some odds and ends. As a followup to our security on Power Macs post, Sophos has a list of viruses and malware listed by OS X version and architecture. Although an alarming number will work on PPC, all of those PPC-capable or Universal malware packages appear to be trojans, so you have to run them; none of the listed compatible attacks can be mounted without user assistance. The trick is to make sure you are not caused to receive them by a drive-by download, let alone execute them, and again, your browser can be a great help (or a horribly effective vector) with such software. Scriptable components like Flash and Java can be caused to download such software under false pretenses if their sandbox protections are subverted -- that is exactly the vector that Flashback used -- and it's yet another reason we need to leave those in the dust.
We are starting to deploy official localizations for German, French and Polish. There is an existing Japanese language pack, but so far they have indicated they would prefer to maintain it separately, and we have not yet heard back from our Chinese (zh-TW) translator. Chris is coordinating our l10n/i18n efforts. Please test these (they are only compatible with 10.0.x) and ensure they work to your satisfaction; I plan to roll these out with 10.0.5. Langpacks will not be offered for unstable branch to reduce load on our localizers.
WebGL nerds will want to look at bug 684882. While looking at 10.5 bugs to determine what we would need to backport in a 10.5-less future, comments 16, 37 and maybe 75 imply what needs to be fixed to enable WebGL and/or OpenGL acceleration on Leopard. I won't be doing this here on 10.4Fx because 10.4 doesn't support OpenGL 2.0 at all, so that's that, but those of you working on Leopard-specific ports including AuroraFox may wish to see if this gives you some pointers. Disabling texture minification appears to be the trick (but it has to be disabled completely) and a putative patch is in comment 16 in that bug. Obviously it will only work on those handful of cards and configurations where OpenGL 2.0 is operational, so this will only benefit a minority of Leopard users with a minority of configurations.
Finally, I am watching Mozilla's progress on Australis, the new Firefox UI. Some of the prerequisites for how the tab bar is to be drawn and designed (bug 625989 and dependencies) have me somewhat worried that there may be no good equivalents on 10.4, and a few comments imply that even 10.5 may have issues with it. It is entirely possible that Australis will land after 10.5 support in Firefox ends (we still don't know when this will be), and if it does, it is guaranteed Mozilla will use 10.6+ APIs of which some are almost certain not to have an effective or extant 10.4 equivalent. As we dropped visual parity with Firefox in 8.0, if it came to that, we would simply just not implement Australis and block installable themes that depend on it.
10.0.5 is holding for some last-minute landings; I aim to have it ready by Friday or Saturday. In the meantime, release notes and architecture builds: