The latest addition to ubuntuupdates.org is the PPAs page. Personal Package Archives are repositories that are not supported in any way by Canonical, but that offer versions of packages that are up to 6 months ahead of the official repositories.

It's sometimes frustrating to have to wait for that long for major new versions of the most popular applications. Take Thunderbird 3.0 for example, it was officially released by Mozilla in December, 2 months after Karmic but is not and will not be part of any official Karmic repository. However it's in the Mozilla Daily Builds PPA and you can install it from there.

As before, UbuntuUpdates.org lets you list all versions of any package in any release. But now, versions of the same package from PPAs are also listed. For example, the MythTV package, part of the Mythbuntu PPA, is shown here alongside official repo versions. The PPA page itself shows the list of member packages and explains how to setup the PPA.

UbuntuUpdates.org doesn't track all existing PPAs (there are thousands, see official launchpad.net PPA website), it only tracks those that appear to be the most popular. If there is a PPA you'd like to see here, leave a comment and I might add it as long as it's not too exotic.

Firefox 3.6 can easily be installed in Karmic from the Mozilla Daily Builds PPA. Just setup the PPA as described here and run

sudo aptitude install firefox-3.6

Then to start the new browser: Alt-F2, and enter "firefox-3.6". All your settings from the regular Firefox will be copied and unchanged in the new installation.

At the time of this writing (1/13/2010), Firefox 3.6 is just a release candidate (RC1). The final version is due to be released this month. The Register has the best review I found on the new features.

The list of Firefox versions available per Ubuntu release is available on the UbuntuUpdates firefox search page. As a reminder, the officially supported version of Firefox in Karmic will stay at 3.5. You install other versions at your own risks. Firefox-3.6 is branded as "Namoroka" in Ubuntu 9.10.

PHP5 got security updates in Karmic and all other supported Ubuntu releases. The new version is 5.2.10.dfsg.1-2ubuntu6.4. The patches are for:

• CVE-2009-2626
• CVE-2009-4142
• CVE-2009-4143

2.6.31-17 was just released as an update (in 'proposed' on 12/10/2009, in 'updates' on 1/6/2010) but 2.6.31-18 is already knocking at the door. It just got into 'proposed'.

The full list of 2.6.31.18 changes is listed on the linux package page. There is a very long changelog, this kernel version cumulates changes from upstream versions 2.6.31.7, 8 and 9.

What stands out is the amount of changes related to ext4. Other than that, the fixes are spread out across all areas of the kernel.

Here's an extract from launchpad.net bug 480144:

SRU Justification/Impact: The upstream process for stable tree updates is quite similar in scope to
the Ubuntu SRU process, e.g., each patch has to demonstrably fix a bug, and each patch is vetted by 
upstream by originating either directly from Linus' tree or in a minimally backported form of that patch.
The 2.6.31.6 upstream stable patch set is now available. It should be included in the Ubuntu kernel as 
well.