This is the default interface of Moun Package Manager. It is a lot more cluttered than any other package manager I have used. That aside, the distinction between it and the Muon Software Center I find to be completely unnecessary. All the features of Moun Package Manager could easily have been implemented in Moun Software Center, giving users just one interface for managing applications. Moun Package Manager adds to real value to the package management in Kubuntu.
Muon Package Manager

Managing The System: Most of the of the graphical management tools are accessible from System Settings. This is the KDE control center, where the tools are arranged in a logical order. A screenshot of it is shown below. Moun Package Manager, Moun Software Center, and several others not listed in System Settings, are accessible from the menu (Applications > System).
Kubuntu System Settings

The user management tool, accessible from System Settings (under System Administration section), makes it easy to create and edit user accounts on the system. It has better features than the equivalent tool in Ubuntu or other distributions that use the GNOME 3 desktop environment. You can, for example, enable or disable an existing account.
Kubuntu 11.10 User Manager

And setup password aging and expiration, two features key to implementing a robust security policy.
Kubuntu 11.10 Password Aging

The first time an attempt is made to login with a new user account, the user is forced to change the password. Note that this does not apply to the user account created during installation.
Kubuntu Change Password Prompt

The change password window displayed after clicking OK in the previous screenshot.
Kubuntu Change Password

How Secure Is The System: Kubuntu 11.10 has the same security profile as Ubuntu 11.10, which means that out of the box, only one port (631, for cupsd, the printing daemon) is open, but listening only on the local network. The firewall is active, but a graphical interface for managing it is not installed. AppArmor, an application-level “firewall”, is loaded, with 8 profiles and 3 processes in enforce mode. If you do not enable any service after installation, the default security posture is pretty good.

If you want to put up a comprehensive security front, that is, accounting for both physical and network security, then you would want to install your system with the Alternate Installer edition, which has support for setting up disk encryption during installation. There is a published tutorial for setting up encrypted LVM in Ubuntu here. The same instructions also apply to Kubuntu or any other officially-sponsored Ubuntu-based distributions with an alternate installer edition.

Final Thoughts: If you cannot stand Ubuntu and the Unity Desktop, Kubuntu is a good alternative. You still get to use “ubuntu,” but with a better desktop environment, which just happens to be one of the best KDE distributions released this year. Unfortunately, I have not been able to install the Takeoff Launcher and Stackfolder on my test installation.

Resources: Links to all download options are available here. You may read the Release Notes, find support links here and post support questions on Questions and Answers.

Screenshots: View more screenshots from test installations of Kubuntu 11.10.

A view of the desktop from the KDE Plasma Netbook interface.
Kubuntu 11.10 Netbook Desktop

Another view showing installed office applications.
LibreOffice on Kubuntu 11.10

And one of the main desktop with a different wallpaper. It is that time of the year, or at least getting close in some regions.
Kubuntu KDE Snow Wallpaper