CD Linux Server is an embedded Linux system on a bootable live CD. It can be used to set up mail, Web, file, FTP, proxy, DHCP, DNS, MySQL, LDAP, and other services very quickly. The mail server includes antivirus, antispam, and mail recorder features. It can be used for free for up to 10 accounts, while the advanced version is licensed for an unlimited number of users. There is not any restriction against the time.
Pure FTP Server is a fast, production quality, standards-conformant FTP server based on Troll-FTPd. It has no known vulnerability, it is trivial to set up, and it is especially designed for modern kernels. Features include PAM support, IPv6, chroot()ed home directories, virtual domains, built-in 'ls', FXP protocol, anti-warez system, bandwidth throttling, restricted ports for passive downloads, an LDAP backend, XML output, and more.
NASLite is a Network Attached Storage (NAS) server operating system designed to transform a basic computer into a dedicated file server. Utilizing highly optimized versions of Samba, uCLibc, BusyBox, and various other Linux tools, it provides SMB/CIFS, FTP, or NFS filesystem support. It accommodates multiple client OSes: Windows, Mac OS X, and Linux. NASLite offers SMART disk monitoring and large file support, and is incredibly easy to install and administer.
Unison is a file-synchronization tool for Unix and Windows. It allows two copies of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. Unison can deal with updates to both replicas of a distributed directory structure. Updates that do not conflict are propagated automatically. Conflicting updates are detected and displayed. Unison can communicate through a direct socket link or through an rsh/ssh tunnel. It uses network bandwidth efficiently.
tcpick is a textmode sniffer that can track TCP streams and saves the data captured in files or displays them in the terminal. It is useful for picking files in a passive way. It can store all connections in different files, or it can display all the stream on the terminal (using colors too).
Aftpd is an FTP server for anonymous access designed for Unix-like operating systems. It uses an asynchronous model of connection processing and provides service for all users within a single process; can use multiple threads to run more efficiently on multi-core systems, with each thread serving multiple clients simultaneously; uses effective mechanisms of transferring files, minimizing copying of data in RAM (sendfile or a combination of the system calls mmap/writev); uses effective event notification schemes (kqueue on FreeBSD and epoll on Linux); uses poll or select in older systems; and supports IPv6. For safety, it works as an unprivileged user and uses chroot.