GParted

GParted manages disk partitions in a graphical interface: it creates and deletes partitions, grows and shrinks them without losing data, moves and copies them, and formats them in many file systems such as NTFS, FAT32, exFAT and ext4. The usual way is GParted Live, a small system booted from a USB stick, so it also serves Windows PCs, for example to enlarge drive C after moving to a bigger SSD or to repair a partition table. Limitations: it has no automatic system cloning like commercial tools, and a wrong operation can erase data, so back up before any change.