Wubi is an unofficial Windows-based free software installer for Ubuntu, licensed under the GNU GPL. The goal of the project is to assist a Windows user unacquainted with GNU/Linux in trying Ubuntu without risking any loss of information due to disk formatting or partitioning. Wubi can also uninstall Ubuntu from within Windows.
It is not a virtual machine, but rather, it creates a stand-alone installation within a loopmounted partition, like Topologilinux does. It is not a Linux distribution of its own, but rather an installer for Ubuntu.
Wubi does not install Ubuntu directly to its own partition (which the developers consider a feature), and it cannot use free hard disk space to install the OS. However, this can be accomplished by using LVPM to transfer the installation to a partition.
So, what is this Ubuntu thing Wubi installs?
Ubuntu is a predominantly desktop-oriented Linux distribution, based on Debian GNU/Linux but with a stronger focus on usability, regular releases, and ease of installation. Ubuntu focuses on usability, including the widespread use of the sudo tool for administrative tasks.
Ubuntu furthermore emphasises accessibility and internationalization, to reach as many people as possible. Besides standard system tools and other small applications, Ubuntu comes with the pre-installed software OpenOffice.org, the internet browser Firefox, and the raster graphics editor GIMP. Several lightweight card and puzzle games are included. Also included are multimedia players such as Totem (movie player) and Rhythmbox (audio player). Up to about 20 000 applications are avalaible after hard drive installation.
Ubuntu aims to use only free software to provide an up-to-date yet stable operating system for the average user.
Wubi lets you choose between different "flavors" of Ubuntu. These are various desktop environments with a different graphical user interface and with a slighty changed bundled applications. See the homepages of Kubuntu, Xubuntu, Edubuntu, and UbuntuStudio for more information.
Currently, only the i386 (32-bit x86) release of Ubuntu can be installed by Wubi, though the installer can be run on both 32-bit i386 and 64-bit amd64 host operating systems.
Wubi requires 256 megabytes of RAM, and, when installed to the hard disk, needs 4 gigabytes of hard-disk space. An Intel/AMD processor with at least 1 GHz or faster should be fine.
Source code for Wubi is included (named Wubi-7.04.04-src.tgz).