Wikipedia
FTOS
FTOS or Force10 Operating System is the firmware family used on Force10 Ethernet switches. It has a similar functionality as Cisco's NX-OS or Juniper's Junos. FTOS is running on NetBSD.
As part of a re- branding strategy of Dell FTOS will be renamed to Dell Networking Operating System ( DNOS) 9.x or above, while the legacy PowerConnect switches will use DNOS 6.x: see the separate article on DNOS.