Using FireFox, you click on a PDF file and you get a popup from Adobe that states "Adobe Reader cannot show documents in this browser."
The Firefox plugin for viewing PDF files has been disabled by Mozilla.
Users can install 3rd party PDF plugins if they want to view PDFs in Firefox. Schubert-It is recommended by Mozilla.
To download Schuber-It, go to http://www.schubert-it.com/pluginpdf.
Use ‘Educational use only’ to avoid ordering the license.
More information about the Mozilla support article can be found at (http://support.mozilla.org/en-US/kb/view-pdf-files-firefox-without-downloading-them).
Both Safari and Chrome browsers use “Preview” as the default PDF browser plugin.