DocuFarm is a Firefox extension that allows you to view different types of documents right from your web browser, even if you don't have the appropriate viewer for those specific file formats.

DocuFarm will be loaded automatically when launching Firefox and will come into action any time you click on a PDF, PPT, DOC, RTF or PS file, displaying the document in a new tab. Just clic on any page to zoom it in and read it more comfortably. You'll also have a link to the original document in case you want to download it.