Most notably, this update includes a built-in PDF viewer, making former PDF viewing plug-ins obsolete. The viewer was built using HTML5 and will provide a quicker, more secure way to read PDFs in the browser.
Firefox 19, which comes more than a month after Firefox 18, also includes remote debugging, bug fixes, and CSS improvements. While the official release notes have yet to be posted, the beta notes are available:
-Built-in PDF viewerThe official launch of Firefox 19 will take place tomorrow, on February 19. The updated version of the browser will be available for download from the Mozilla website.
-Canvas elements can export their content as an image blob using canvas.toBlob()
-Startup performance improvements (bugs 715402 and 756313)
-Debugger now supports pausing on exceptions and hiding non-enumerable properties
-Remote Web Console is available for connecting to Firefox on Android or Firefox OS (experimental, set devtools.debugger.remote-enabled to true)
-There is now a Browser Debugger available for add-on and browser developers (experimental, set devtools.chrome.enabled to true)
-Web Console CSS links now open in the Style Editor
-CSS @page is now supported
-CSS viewport-percentage length units implemented (vh, vw, vmin and vmax)
-CSS text-transform now supports full-width
-Starting Firefox with -private flag incorrectly claims you are not in Private Browsing mode (802274)
Update: The FTP link has been removed. Firefox 19 is now officially available from the Mozilla website.