How many times have you downloaded a file off the internet? I'll bet you just clicked a link and the downloaded started automatically. You probably didn't notice the URL as it flashed across your screen, but there's a good chance that it was an FTP address.

You know about FTP, don't you? FTP stands for File Transfer Protocol, and it is a very efficient way to copy files over the internet. It's far more efficient than the standard HTTP protocol (the way your browser transfers information). Because of that, you will find FTP addresses buried in web sites all over the internet.

Most of the time, these are anonymous FTP sites, which means you do not need a username and password to get the files. You see, you can set up FTP to require a username and password - this is perhaps the most common way people get information loaded up to their web site.

However, if you want you can remove the username and password requirement to allow anyone to get access to your files. Most of the time an anonymous FTP site only allows files to be downloaded from the site: finding one that allows uploads is very rare as this means anyone can add information at any time.

It's easy to log into an anonymous FTP sites. Sometimes no username or password is required at all, and sometimes you just enter "anonymous" and a password of your email address. Once you do that using your favorite FTP client (or just Internet Explorer), you can have a great time looking through what's available.

Why would anyone want to use FTP instead of just loading some web pages? Besides the fact that FTP is more efficient, it's also very easy to maintain. An FTP site is structured very much like your standard file system, with directories (or folders) and files, along with folder-level security (the ability to require a username and password on selected folders or directories). That's about all there is to an FTP site. It's very simple to maintain, relatively secure (as long as you don't allow people to upload or write) and easy for visitors to understand.

You will find fully anonymous FTP sites are common in situations where large numbers of files need to be made available to the general public. These include support sites which post patched versions of software, desktop themes and screen savers and volumes of documentation.

The wealth of information that is available from these sites is huge. It can be an incredible pleasure to explore the files available on one of these sites. One of the things that makes them so pleasurable is no one has gone through any great effort to make a good presentation (as with a web page). Thus, what you see is raw files containing information, and not pretty web pages.

Some great anonymous FTP sites and FTP site lists include the following:

Swedish University Network's, FTP archive ftp://ftp.sunet.se/pub/ One of the truly great FTP sites. Tons of files freely available for download.

Archive-name astronomy-ftp-sites http://www.seds.org/pub/faq/astroftp.html List of FTP sites with information for people interested in astronomy.

Perry's FTP-List Page http://home.iae.nl/users/perry/ftp-list.html List of hundreds (if not thousands) of FTP sites.

Introduction Exhaustive List of FTP Sites http://hoohoo.ncsa.uiuc.edu/ftp/intro.html Another list of lots and lots of FTP sites.