WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.

nmon - This systems administrator, tuner, benchmark tool gives you a huge amount of important performance...

TreeSize - TreeSize tells you where precious disk space has gone to.

gtop - System monitoring dashboard for terminal

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.

psutil - psutil is a module providing an interface for retrieving information on all running processes and...