What is Kde4?
1.
A new sleek, open source, smooth looking Graphical User Interface for Linux kernel based operating systems.
Rewritten from scratch by the KDE team, because of the age of the old kde code.
Released offically January 11,2008
Has many programs used for education, web browsing, and a new file browsing program called Dolphin.
Highly customizable desktop
Is susposed to be as easy or easier on memory than KDE 3.5. Should kick vistas ass in the end in terms on performance, features, and being Free for anybody.
Is a counterpart, and somewhat a rival to Gnome GUI, which is also open source.
And example would be... Kubuntu's new operating system will utilize kde4, while Ubuntu's new os will utilize the latest Gnome gui.
See