Learn more at www.freeshell.org

SDF is also an acronym for a "free", publicly funded UNIX server. According to the website, the system has been in operation since 1988 (presumably on dialup).

Application is simple. Log onto sdf.lonestar.org using "plain" telnet, and make a temporary account. This interim account is limited to pine, ls, dir, and cd, so it isn't the idea base for any sort of malicious behavior.

If so inclined, you can send in one dollar, one euro, or equivalent to some shady P.O. Box. Of course, practice common sense when sending green stamps through the USPS. This uprated account gives you a pretty wide selection of commands including mkdir and rm, as well as elm, tin but alas no telnet. The website for SDF gives more info on how to trade money for more commands, and even a good share of server space. Again, this is at the user's discretion.

In my few months of using SDF, service has been good. The only delays in service have been for server or equipment upgrades. The owners make themselves available, and things seem pretty legit if, again, one practices a bit of healthy identity protection. There are some nice advantages to having a real server to plop mailing lists on, most of all a bit of freedom from endless reams of spam that can plague Web based "free" email services.