PDF24 has a Java based online PDF Reader which you can use to open PDF files within your browser. The cool thing about the tool is that you can open any supported file which the PDF24 Online PDF Converter supports. The tool converts your file to PDF in the background in order to display it.
Free Online PDF Reader from PDF24
PDF24 provides a free Java based online PDF viewer which runs directly in your browser. You do not need to install any other software. The PDF reader can read and show PDF files. The reader has a toolbar with a lot of nice features. You can rotate, zoom, view in full screen mode, print a PDF and so on. The PDF reader is free for everyone.