3D FileSystem Profiler
   Provides 3D visual representation of file system statistics. Aids in visual analysis of the disk space usage. [Java based]
   http://visualversion.com/profiler/index.html

Ascendis DiskVision
   Displays disk space utilization with detailed information. Supports easy management on individual files and folders. [Windows 95/98/NT4/2000]
   http://www.ascendis.com/diskvision/diskvision.html

BAC WhatsGone
   Does a scan of the selected disc or folder and then gives a color coded view of the disc space used by each folder. Includes CSV export option. [Windows 9x/2000/ME/XP]
   http://www.bacsoftware.co.uk/whatsgone/home.htm

BytesBak
   Maintains a history of disk space usage, allowing easier identification of disk contents that have been updated, grown or shrunk in size.
   http://www.bytesbak.com

Directory Sizer - FranzO Software
   Historical analysis of disk usage by directory. Charting and drill down with web UI. Designed for the enterprise with NT Services and remote install.
   http://www.franzo.co.nz/dirsizer2/

Dirlot - free folder size visualization utility
   Shows relative size of files and subfolders in a folder on disk using interactively explorable and colorful diagram report. [Windows 98/ME/2000/XP]
   http://soft.km.ua/soft/dirlot/index.en.html

Diruse
   Command-line tool that displays directory size information, including compression information for NTFS volumes. [Windows 2000 with NTFS volumes]
   http://www.microsoft.com/windows2000/techinfo/reskit/tools/existing/diruse-o.asp

Disk Recon
   File management tool that includes folder sizes, file search, duplicate file finder and file monitor. [Windows 98/ME/2000/XP]
   http://www.blacksunsoftware.com/diskrecon.html

Disk Size Manager
   Provides pie and bar charts of disk usage in a file manager interface. Includes a tool to conditionally search files and folders. [Windows 9x/2000/NT/ME/XP]
   http://www.spadixbd.com/dsm/

Disk Triage
   Disk space sizing and analysis utility. Features visual graphs of the sizing data, with the ability to run in batch mode.
   http://www.timeacct.com/disktriage/

Disk Usage Explorer
   A program to visually show the disk space distribution
   http://siddharth.homeip.net/due/

DiskSpaceChart
   A small shareware utility that shows a 3D pie chart indicating disk space usage. [Windows 9x/ME/NT/2000]
   http://www.silurian.com/win32/chart.htm

DiskView
   Integrates with Windows Explorer to present visual indication of disk usage. Provides a visualizer pane for pie/bar charts, adds folder size columns in the details view, and size indicator bars in Explorer's tree view. [Windows 2000/XP/2003]
   http://www.diskview.com/diskview.htm

Diskdata
   Explorer-like application that displays disk space utilization in report or chart format. [Windows 9x/NT/2000/ME/XP]
   http://www.digallery.com/diskdata/

Drive x-Ray
   Drive x-Ray is a visual tool for finding and freeing disk space.
   http://www.tdp.cz/products/xray.shtml

Filelight
   Filelight is an open software that shows your filesystem as a set of concentric pie-charts. [Unix]
   http://www.methylblue.com/filelight/

FolderSizes
   Shareware that creates visual representations of hard drive space utilization and folder sizes through multi-threaded analysis engine. [Windows 95/98/ME/NT 4.0/2000/XP and Internet Explorer]
   http://www.foldersizes.com/

FreeSpace
   Monitors hard disk free space in real time. [Windows 9x/NT4/2000]
   http://www.pro-jets.it/en/freespace/index.htm

Junkfind
   Cross platform tool that helps graphically find and remove folders that take up excessive space. Uses rectangular boxes to represent folders based on their relative size.
   http://junkfind.kniberg.com

MBS Disk Space Analyzer
   Disk space analysis and cleaning software for Windows 98/ME/XP.
   http://www.craveworldwide.com

O&O DiskStat
   Displays disk usage as rendered 3D bar, doughnut, and treemap charts, optionally grouped by file type or owner. [Windows 2000, XP, 2003, Vista]
   http://www.oo-software.com/home/en/products/oodiskstat/

OmniDiskSweeper
   A utility for finding and deleting big, useless files to free up space on your hard disks. [Mac OS X]
   http://www.omnigroup.com/applications/omnidisksweeper/

Power Admin WatchDisk
   Tool with command line support for keeping track of disk usage on a network. Provides graphical reports of disk usage, automated alerts and data export options.
   http://www.poweradmin.com/watchdisk/watchdisk.asp

Rakersoft SpaceTrack
   Disk utility that tracks, monitors and records disk space usage on a continual basis. Product specifications, screenshots, and downloads. [Windows]
   http://www.rakersoft.com/

ShowSize
   ShowSize lets you see folder sizes, unused files, and also lets you print folder contents. [Windows 98/Me/2000/XP]
   http://www.showsize.com

SizeExplorer
   Explorer style software that shows the actual space used by a folder. Shows graphical charts of file statistics [Windows 9x/ME/NT/2000]
   http://www.sizeexplorer.com

SizeWatch
   Dynamically keeps an eye on the sizes of selected subdirectories. [Windows 9x/NT]
   http://www.ahc.dk/eng/share.htm

Space
   Disk usage analysis tool for Windows. Shows graphically how disk space is being used. Works on local and network drives, and FTP accounts.
   http://www.andyhsoftware.co.uk/space/

SpaceMonger
   Displays files and folders as boxes, with sizes relative to space taken on disk. [Windows 9x/NT/2000/ME/XP]
   http://www.sixty-five.cc/sm/

SpaceObServer
   Hard disk space manager for Windows. Scans directory trees and stores the collected data in an SQL database. A user interface reports space usage, growth and more in tabular views, 3D bar, pie and line chars. Integrated file search.
   http://www.jam-soft.com/spaceobserver/

SpaceSearcher
   Analyzes space usage on drives or network share drives. Detailed reports and 3D bar charts of hard drives can be viewed, printed, and exported to Excel or HTML.
   http://www.coolutils.com/SpaceSearcher

TreePie
   Program to graphically display information about distribution of size in a tree directory.
   http://treepie.sourceforge.net/

TreeSize Professional
   Hardisk space manager for Windows 95/98/NT. Shows folder or drive size, wasted space, 3D bar and pie charts, last access date, searches for old, big files. Explorer-like interface, Excel or text export, context menu support. English or German shareware fr
   http://www.jam-software.com/treesize/

WheresTheFreeSpace
   A hard drive free space analysis tool for Mac OS X
   http://www.wheresthefreespace.com

jDiskReport
   Cross platform graphical disk report utility to analyze hard disks and collect statistics that can be viewed using charts and tables. [Free: Windows/Solaris/Linux]
   http://www.jgoodies.com/