UDPCast allows to send data simultaneously to many destinations on a local net. This can for instance be used to install entire classrooms of PCs at once. The advantage over using other methods (nfs, ftp, whatever) is that udpcast uses Ethernet's multicast abilities: it won't take longer to install 15 machines than it would to install 2. The tool comes with a busybox bootdisk for easy loading of the tool. However, udpcast can also be started from the command line of an already installed system, and can be used for other purposes than just system installation.
imapsync is a tool for facilitating incremental recursive IMAP transfers from one mailbox to another. It is useful for mailbox migration or backup, and reduces the amount of data transferred by only copying messages that are not present on both servers. Read, unread, and deleted flags are preserved, and the process can be stopped and resumed. The original messages can optionally be deleted after a successful transfer.
apt-got is a customizable mirror engine. It works like a highly specialized proxy. It employs several pluggable modules that are customized for specific jobs. The first available module builds and supervises a partial (or full) Debian mirror which is populated on-the-fly by apt-get requests. There is also a simple mirror module that can be used to mirror source directories or even (static) Web pages. For increased performance on already-cached files, it employes its own Apache module. It supports customized mirroring algorithms.
AnomicFTPD is an RFC959-compliant FTP server with OS- independent user and group management. Active and passive modes, non-root mode, and anonymous and/or read-only modes are supported. A built-in client IP filter acts as a firewall and provides additional access limitation. The server has no online interface; attributes, groups, and user accounts are configured through text files. The protocol/ format-unspecified LIST command produces output that is compatible with most FTP clients, including common Web browsers in FTP mode.
FDT is an application for efficient data transfers that is capable of reading and writing at disk speed over wide area networks (with standard TCP). It can be used to stream a large set of files across the network, so a large dataset composed of thousands of files can be sent or received at full speed, without the network transfer restarting between files. It is written in Java, runs an all major platforms, and is easy to use.