JNC (JavaNativeCompiler) is a Java to native compiler. It allows ahead of time compilation of your Java applications. With JNC, you can create real standalone native binaries which will no longer depend on a JRE. This is especially useful when applications have to be deployed to end users. Native applications are easier to deploy since the end user doesn't need to worry about JRE dependency. They are also harder to decompile, and they load more quickly.
FREP is an application which can be used to keep files in a cluster of servers synchronized from a centralized location. Under the hood, it uses the Spread toolkit (broadcast/multicast traffic), libevent/epoll, sendfile, inotify, intelligent file transfers using the generic diff format, and zlib compression.
Devalot is a social networking application centered around software projects. It connects the user community with the development community and encourages participation and communication. It includes all the features you've come to expect in modern Web-based applications such as tagging, comments, and a wiki, as well as features you'd expect in project tracking software such as ticketing. It has features similar to some of those found in Trac, Collaboa, GForge, Mephisto, and Typo.
PHP Tarbackup is a simple class that allows backing up an entire Web site. It automatically works around timeout limits by splitting the job into multiple requests, allows tarball archive creation and updates, and comes with the Veloce script, which is very useful to automatically unpack tar.gz archives remotely and skip long waiting times due to FTP uploads.