Adobe Reader and the Portable Document Format (PDF) revolutionized Internet in such a great way that from initial download size of 2 MB, it reached to 32 MB with version 9.0.  And installed size of the program, sometimes, reaching as far as to 133 MB made it difficult to open files easily on the computer and it takes too much time to open a PDF file.  Following are some of the lighter versions of the PDF file.

FoxIt Reader (Download Size: 3.56 MB, Installed Size: 7.14 MB):  Similar to Adobe Reader in layout and functionality you can add notes, zoom, search on text, view images and more. Above all it is very quick and fast to open. Its more advanced features can be downloaded with FoxIt’s update and eBay toolbar.  And it really has more than 50 million downloads so far.

PDF-Xchange Viewer (Download Size: 17.9 MB, Installed Size: 25.5): With the features of being customized by users PDF –Xchange Viewer has all the features of FoxIt, though its download is bit bigger and takes much space after installation.

Perfect PDF Reader (Download Size: 22.4 MB, Installed Size: 14.6 MB):    With some additional softwares to write and interface similar to Office 2007 Perfect PDF Reader finally arrives as a PDF reader. And is not recommended in most of reviews.

Cool PDF Reader (Download Size: 632 KB less than 1 MB, Installed Size: 632 KB):  Cool PDF Reader opens straight after execution as PDF reader. Lets to read as well as added with other features like zoom in, zoom out, page forward and backward. It is also possible to run it from a USB drive.

It is up to you to decide upon which one is the best version after using then itself.