htop - htop - an interactive process viewer for Unix. This is htop, an interactive process viewer for Unix systems. It is a text-mode application (for console or X terminals) and requires ncurses. Latest release: htop 2.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Windows Task Manager - Need assistance with your Microsoft product? Find helpful articles for Windows, Office, Microsoft Account, Microsoft Store, Xbox, and more.
TreeSize - TreeSize tells you where precious disk space has gone to.
GNOME System Monitor - System Monitor is a tool to manage running processes and monitor system resources.
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.