Note that there are other sections which may carry software that would quite justifiably go here. For instance, there is the File Archivers/Compressors section, but that software may be critically useful for more general purposes and so is listed on TOOGAM's Software Archive page more prominently. Information on other utilities such as undelete utilities might be located in the Operating Systems section.
There are many types of utilities that might go here (such as disk compressors, undelete utilities, etc.) For now, though, this section is still fairly small:
There is currently a page about Bit Manipulation Tools (Binary File Editors).
Looking to see how free space is used up? After the program WinDirStat analyzes a disk (which may take some time), the interface shows more information (than what it does during the disk analysis) and provides a nice interface showing what extentions use up the most space (both numerically where extentions are sorted by disk usage in the upper-right corner of the display, and by color in the lower part of the display) and a visual indication of files by size (so gigantic files will probably be able to be visibly seen). This sort of visual layout has been given the term “treemap”, by research where the term treemaps comes from which is referred to by the WinDirStat page. WinDirStat web page (which is the current version of WinDirStat Setup (ANSI for Win9x/ME, Unicode for NT4SP5/2K/XP/2003) (which has been version 1.1.2 for years) is nicer than the KDirStat it is based off of. WinDirStat shows which type of extention uses the most space. To maximize colors, go to Options, “Configure WinDirStat...”, “Directory List”, and lower the slide bar from “Tree Level 4&rduqo; down to the maximum value (“Tree Level 8”). While on that same screen, one may choose to check “Show Time spent during the Scan”. Doing so will cause a time (such as “[0:57 s]”), insetad of a percentage, to show up in the “Percentage” column during the scan. After the scan, the entries for the sub-folders do change to show percentages instead of the time spent on each sub-folder. The top-most folder (which may be “My Computer”) continues to show the scan time instead of showing the already-known information it has 100% of the total of whatever was scanned.