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.
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.
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).
MultiLoad is a load balancer that redirects HTTP requests to pre-defined servers/locations. It gives the provider a way to balance the traffic and hides the real download location. It allows you to manage different version of each download. It is also a load balancing server extension. You can distribute files on some servers so that a downloaded file can be loaded form different servers. These servers can have different priorities to control the active traffic.