"Filelight is designed for KDE, but will work in other desktop
environments. The latest version hails from September 2006, though
a KDE 4 version is (vaguely) promised; the author is "getting round
to it." Filelight is included with most distributions, so
installation is easy via a package manager. Filelight also works as
a Konqueror plugin; once you have installed it, Konqueror will
enable a new view mode: check View > View Mode -> Radialmap
View.
"Filelight represents your disk as a circle, and each directory
has an arc proportional to the space it's using. Colors help
differentiate the directories. Subdirectories appear at an outer
level, in concentric rings, but if a directory has too many files,
a black triangle will appear instead. Hovering the mouse over an
arc sector produces a popup that shows the full path of the
corresponding directory, its size (both in megabytes and as a
percent of the total space), and the number of files in it.
Clicking on a sector works recursively; the selected directory
becomes the circle, and you can see more detail. Right-click on a
sector for a context menu that lets you delete a directory or
file."
