ZTree (as it's now known) is a powerful 32bit & 64bit text-mode file & directory manager, available in three versions: ZTreeWin v2 for Windows NT, 2000, XP, Vista & Windows 7 & 8, ZTreeWin v1 for 95, 98 & ME, and ZTreeBold for OS/2 and eComStation.
Those who remember X-Tree (Standard/Plus/Pro/Gold) will remember how easy it made file management under DOS.
Symantec bought the product, created a GUI Windows version (which sucked, really), and then killed it off when Win9x showed up.
One of the many people who missed X-Tree's functionality did something about it, so now we have Z-Tree.
Z-Tree has, in fact, been blessed by the original author of X-Tree (and there's a whole story there, which includes such things as X-Tree for Unix).
For anyone who's found WindowsExplorer? just not quite up to the task of file management as $CREATOR intended should look into Z-Tree.
For those who can't kick the mouse, there's always FreeCommander, which has filtering, viewing, and such.