When Kpackage is started normally (that is it has not been invoked via drag and drop and has not been given any parameters) it displays two panels with the package tree on the left, this tree shows installed packages and optionally uninstalled and updating packages as well.
The package tree show the package name, package size, the version and (in the case of an uninstalled package which would update an installed package) the version of the already installed package.
Selecting a package from the tree displays information about it in the right panel and allows:
Displaying the status information on the package
Seeing which files are included in an installed package, selecting a file from the list will open it using the file manager
Verifying files in a package, files that exist are marked with a tick, files that don't with a cross.
Uninstalling an installed package
Installing an uninstalled package
The package tree can operate in two modes:
in Single Select mode selecting one packages deselects the previous one
in Multiple select mode many packages can be selected and these can be installed or uninstalled as a group