It's official, Firefox 19 is here. The latest and greatest version of Mozilla's browser is now available for download on the homepage, it was made available through the FTP servers earlier, and it should start making its way to existing users via the automated update system.
There's not much to brag about in Firefox 19, the built-in PDF viewer is finally enabled by default, so you won't need a plugin or a desktop reader for most PDF files anymore.
Mozilla has backed down on the integrated download panel, another feature that's been a couple of years in the making.
You should be seeing an improvement on startup speeds though and there are some under-the-hood improvements as well, mostly of interest to developers.
On the mobile front, Firefox 19 is the first to support older ARMv6 processors working at frequences as low as 600 MHz, meaning the browser can be installed on 15 million more devices than before.
Firefox 19 for Android also adds support for the lightweight themes the desktop Firefox has supported for a few years now.