The World Wide Web is great for transferring straightforward text, but the usual way of doing this (using something called Hyper Text Markup Language, or HTML) isn't much good when it comes to preserving the look of a document, e.g. its layout and fonts. When it's important to preserve the original look of a document, some other strategy is needed. One possibility of course is to make the document available in the "native" format of whatever program created it (e.g. as a Microsoft Word file), but this has drawbacks too. The first is that there are incompatible versions of many programs, or the programs may only run on a particular type of computer (a PC or a Mac for example). Even if you have the right program, you may not have the same fonts installed as the person who created the document in the first place, so again, you won't see what the author intended.
There are a number of products which attempt to solve this problem. One of them is Acrobat* from Adobe Systems Incorporated. Acrobat pdf files retain the original look of a document, regardless of whether you have the application that created it, and regardless of whether or not you have the same fonts that were used to create the document. There are an increasing number of files appearing in pdf format on the Web, and so downloading and installing the software now means that you will be able to view not only the files on this site, but many others as well. All of the pdf files on this site need version 3 of the Acrobat Reader. Using previous versions will cause a variety of (weird) error messages.
You can download the free Acrobat Reader here
If you have Netscape 3.0 or later, or Microsoft Internet Explorer version 3.0 or later, the Acrobat Reader will function like a plug in. That is, when you click on a pdf file, it will display in your browser's window. If you have a different, or older browser, then you will need to configure the Acrobat Reader as a helper application. Check the online help in your browser for details of how to do this.
*Acrobat and the Acrobat logo are trademarks of Adobe Systems Incorporated