Firefox 3.6 has just been released today and i have updated to the latest release using automatic updates (ie. i'm not using Slackware's Firefox package). This release brings many improvements to Firefox 3.x releases, with multiple personas, WOOF font format, PluginCheck, improved HTML 5 and CSS 3 support, including CSS Gradient, and many more. In short, it's a must-have upgrade for this week.
Unfortunately, some add-on or extensions will be broken due to some changes in Firefox 3.6 which should force the extension developers to change their code a little bit in order to make it compatible with Firefox 3.6. So far, only two of my add-ons which are not compatible (yet).
Other things to consider before moving to Firefox 3.6 is how Java application interacts with Firefox 3.6. It has been stated on many media that Firefox 3.6 changes the Java Plugin, so libjavaplugin_oji.so will not longer recognized when you type about:plugins in the address bar. You will also need to upgrade your Java installation to Update 10 or above. The latest version up to the time i write this post is Update 18.
To have Java apps working again in Firefox 3.6, you will have to go to Plugins directory of your Firefox installation (mine is in /opt/firefox/plugins), and then run ln -s /usr/java/jdk1.6.0_18/jre/lib/i386/libnpjp2.so . (note the dot and also the path to Java will be different if you are using Slackware's Java package). That's it and your Java application will work as it used to be.
Credit: Iain Curtain