Git is a "directory content manager" that was designed to handle massive projects such as the Linux kernel with speed and efficiency. It falls in the category of distributed source code management tools and is similar to GNU Arch, Monotone, and BitKeeper. Every Git working directory is a fully-fledged repository with full revision tracking capabilities and is not dependent on network access to a central server.
X-Unikey is a tool that lets you type Vietnamese in an X Window environment. It has been tested with many popular programs such as OpenOffice, emacs, vim, QT, and GTK applications. It has all the features of Unikey, the Windows version, except that its GUI is simplified. All options are set through configuration file or keyboard shortcuts.