There are several FTP servers available for Linux, but three dominate the picture:
BSD FTPD ” The BSD versions of UNIX ship with their own FTP servers, and various ports of these to Linux exist. Some of these are also known as OpenBSD FTPD. BSD FTPD ports ship with Debian and SuSE. This server family is often regarded as more secure than other FTP servers, but it's not very popular in the Linux world.
ProFTPd ” This package, which is headquartered at http://www.proftpd.org, ships with Debian, Mandrake, Slackware, SuSE, and TurboLinux. It's the second most popular Linux FTP server, and its popularity is on the rise in 2002. Parts of its operation are modeled after Apache.
WU-FTPD ” The Washington University FTP Daemon (WU-FTPD) is the most readily available FTP server for Linux. Its main Web site is http://www.wu-ftpd.org, and it ships with Caldera, Debian, Mandrake, Red Hat, SuSE, and TurboLinux. It has a history of more security problems than other popular FTP servers.
Any of these FTP servers will handle basic or advanced FTP server duties . This chapter describes configuring ProFTPd and WU-FTPD because they're the most popular servers, and all major Linux distributions ship with at least one of these servers. ProFTPd is more flexible than WU-FTPD, and given their relative security histories, ProFTPd is probably a better choice in most situations. You might want to stick with WU-FTPD if your distribution ships with it but not ProFTPd, or if you're already familiar with WU-FTPD. If you're adventurous, you might consider BSD FTPD, but it's really a small family of servers because there are several different ports to Linux. Thus, properly documenting it is difficult.