Firefox 19 is slated to be launched on Tuesday, but as noted by The Next Web, the latest version is already available for download from Mozilla's servers. The U.S. version of Firefox 19 for the Mac can be found in the aforementioned folder by accessing the Mac directory and then selecting “en-US.” 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
