From the name of the distribution, it's easy to conclude that Eeebuntu is a customized distribution of Ubuntu, specially configured for the Eee PC. Unlike the vanilla Ubuntu distribution, Eeebuntu has been modified to run only on an Eee PC, but run well. Using the Array kernel specially created for the Eee PC, Eeebuntu boasts of a 100% working install out-of-the-box. This means that you can just download the ISO, install Eeebuntu on your Eee PC and utilize all the features of your netbook without having to install or configure anything. The Eeebuntu works out of the box on ASUS Eee PC 700, 701, 900, 900A, 901, 904HD, 1000, 1000H and 1000HD.
To cater to different demands, Eeebuntu comes in three flavors: Standard, NBR or Base.
The Standard version bundles a full suite of internet applications like Mozilla Firefox, Pidgin, Thunderbird, an Office suite (OpenOffice.Org) for your office-related work and multimedia applications to watch videos and listen to music. In short, the Standard version is pretty much the "desktop" version of Eeebuntu.
The NBR version bundles the same application suites as above, but instead of using a normal desktop environment, it includes the Netbook Remix launcher, a specially created application launcher customized for the small screen of the Eee PC.
The Base version includes just a stripped down version of the Standard install. The only things present are Gnome, Firefox and a few additional extras. Everything else is removed to keep the install size down and speed up. You can always use the package manager to install applications manually, which means that the Base version gives you more control with your Linux install.
Eeebuntu download page