Kubuntu
Kubuntu is an operating system built by a worldwide team of expert developers. It contains all the applications you need: a web browser, an office suite, media apps, an instant messaging client and many more. Kubuntu also family of Ubuntu,it is =Ubuntu+KDE-->Kubuntu
Kubuntu is an open-source alternative to Windows and Office.

Surf the Internet with Firefox

Users more familiar with the award-winning Firefox web browser can install it using our one-click installation process. With Firefox you can browse faster and safer.
More open-source browsers are available through Kubuntu's software repositories.

Email made easy

Kubuntu uses KMail to let you access your email. Whether it's an important business email or a letter to a friend, KMail's got you covered. KMail integrates seamlessly with your address book and Kontact, one of the productivity suites available in Kubuntu.

The GUI

If you want to download Kubuntu,visit this site:
-http://www.kubuntu.org/getkubuntu