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.
wgrab is a Perl script for for retrieving Web documents from the command line. It allows you to use date-based and/or number-based patterns to specify the documents to download. Regular expressions can be used to restrict which references are to be followed when performing recursive retrieval.
rdiff-backup backs up one directory to another. The target directory ends up a copy of the source directory, but extra reverse diffs are stored in a special directory so you can still recover files lost some time ago. The idea is to combine the best features of a mirror and an incremental backup. rdiff-backup can also operate in a bandwidth- efficient manner over a pipe, like rsync. Thus you can use rdiff-backup and ssh to securely back up to a remote location, and only the differences will be transmitted. It can also handle symlinks, device files, permissions, ownership, etc., so it can be used on the entire file system.
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.
Phrealon is a bootable Linux CD based on Slackware Linux 8.0, designed to allow the easy imaging of multiple workstations. It utilizes the updcast set of Linux tools to accomplish this. It provides an interface that allows users to select options from menus and autodetects most of the supported NICs.
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.
Sequoia provides high availability and performance scalability for databases. It is is the continuation of the C-JDBC project. It provides transparent database clustering (partitioning, replication, etc.). It works with any Java application without code modification and with any database engine. It has been successfully tested with Tomcat, JBoss, JOnAS, WebSphere, MySQL, PostgreSQL, Apache Derby, HSQLDB, SAP DB, Oracle, DB2, Sybase, MS SQL Server, Firebird, and more.