The FTP client built into OS X is activated in the sharing control panel, and uses the system users for login and home directory info. Most configuration is done using the files in /etc/, however there is not much that can be configured. If you want to do stuff like limit the number of logins, you will need a third party FTP client, although I don't know where you could find one.
Actually, the Sharing Preference Pane controls the ftp server, not client.
The ftp client is accessed on the command line (read: via the terminal). It works much like the shell (cd to change directories; ls to list). The to big commands being:
You use it by typing something like:
The best way to learn about it is to type:
or read one of the many Linux/BSD HOWTOs and FAQs floating around out there.
FWIW, I use the command line ftp as my ftp client 90% of the time. It may take a bit to get used to, but as is so often the case with command line tools, it is extremely fast and efficient.
thanks to your knowlegde of there being an ftp client in the console, i now prefer to use the console than an application. for one, its built into the system.... second, its fast, doesnt rely on any third party app, uses console (which you can access even before you login using >console). i only have one question though, if you set up your ftp through the prefs, how do you login? can you set up a guest account? and where do the files come from? thanks for any input.
Not to be pedantic, but ftp is an application, albeit one that runs on the command line. It is however, as you said, very fast and built in.
Now that that's out of the way...
When you turn on the ftp server in System Preferences, It uses the users you create in the Users Preference Pane. So when you connect to your machine (perhaps with ftp localhost) you enter your username (what apple calls your "short name") and your normal password. This applies to any other users you create in the Users Pane. One would assume this includes a user called guest...
Looking over the ftpd man page, it seems your best bet is to create a user called ftp and edit /etc/ftpusers to include the lines: anonymous and ftp. That should set up a "real" anonymous ftp user.
There may be a better way to go about this, speak up anyone who knows it.
It should also be noted that anonymous ftp is a HUGE security hole and you should probably steer far clear of it unless you have a very specific reason for needing it. Using your own username, and/or creating usernames for those who need access should work for most applications and is enough of a security issue by itself. Better still would be to turn on remote login (aka sshd) and use scp (man scp and the scp HOWTOs will be of help here). Too bad there's not a really good graphical scp client...