WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
N2WS Cloud Protection Manager - N2WS is the leading Enterprise-class disaster recovery, and backup solution specifically made for Amazon EC2 servers.
TreeSize - TreeSize tells you where precious disk space has gone to.
Bacula Enterprise - A physical, virtual and cloud data center backup software for data centers. Bacula Enterprise Edition is the best open source backup software.
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.
Nuabee DRaaS - Nuabee DRaaS is an online file backup software that helps your IT business protect your important files and documents across all data centers.