G4L is a hard disk and partition imaging and cloning tool. The created images are optionally compressed, and they can be stored on a local hard drive or transferred to an anonymous FTP server. A drive can be cloned using the "Click'n'Clone" function. G4L supports file splitting if the local filesystem does not support writing files larger than 2GB. The included kernel supports ATA, serial-ATA, and SCSI drives. Common network cards are supported. It is packaged as a bootable CD image with an ncurses GUI for easy use.
Partition Logic is a partitioning and disk management tool for PC-compatible computers. It includes its own standalone operating system and GUI, and can fit on a single bootable floppy (or CD). It creates, modifies, resizes, deletes, formats, and moves partitions, and copies hard disks. It is based on the Visopsys operating system.
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.
Rsyncrypto allows you to encrypt a file or a directory structure such that they can later be synchronized to another machine using rsync. This means that local changes to the plain text file result in local changes to the cipher text file. rsyncrypto compresses the plain text file prior to encrypting it with gzip using the "rsyncable" patch, which is available from the rsync sources.
mrepo (formerly known as Yam) builds a local APT/Yum RPM repository from local ISO files, downloaded updates, and extra packages from RHN (Red Hat Network) and 3rd party repositories. It takes care of setting up the ISO files, downloading the RPMs, configuring HTTP access, and providing PXE/TFTP resources for remote installations. It was primarily intended for doing remote network installations of various distributions from a laptop without the need for CD media or floppies, but is equally suitable for an organization's centralized update server.
changedfiles is a framework for filesystem replication, security monitoring, and/or automatic file transformations--essentially any application where you'd poll files or directories and either do something to them or send them somewhere else (or both). The difference is that the kernel tells you when they change instead of you having to poll. It's an easy real time FTP push mirror to one or multiple sites. It's also a full fledged MySQL client, so you can do realtime database operations (for example, batch imports). It consists of two parts: a kernel module (works with Linux kernel version 2.4) which reports to a device whenever a file on the filesystem changes, and a daemon which runs in user space and can be configured to do almost any action when a change to a file matching the one of the patterns it looks for is reported. The kernel module is SMP safe and has been tested on Intel, PowerPC, and Alpha.
rfs is a shell script for creating and updating a local spare system disk. The main goal is to recover a working system after a crash quickly. In this case, "quickly" means the time it takes to reboot the machine. rfs stands for "replication of filesystems". Like rsyncbackup, rfs is built on top of rsync.
Chiron FS is a FUSE based filesystem that implements replication at the filesystem level like RAID 1 does at the device level. The replicated filesystem may be of any kind you want; the only requisite is that you mount it. There is no need for special configuration files; the setup is as simple as one mount command (or one line in fstab).