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.

Three of the four product families from Dell Force10 are using the Broadcom Trident+ ASIC's, but the company doesn't use the API's from Broadcom: the developers at Force10 have written their own Hardware Abstraction Layer so that FTOS can run on different hardware platforms with minimal impact for the firmware. Currently three of the four F10 switch families are based on the Broadcom Trident+ (while the fourth—the E-series—run on self-developed ASIC's); and if the product developers want or need to use different hardware for new products they only need to develop a HAL for that new hardware and the same firmware can run on it. This keeps the company flexible and not dependent on a specific hardware-vendor and can use both 3rd party or self designed ASIC's and chipsets.

The human interface in FTOS, that is the way network-administrators can configure and monitor their switches, is based on NetBSD, an implementation which often used in embedded networking-systems. NetBSD is a very stable, open source, OS running on many different hardware platforms. By choosing for a proven technology with extended TCP functionality built into the core of the OS it reduces time during development of new products or extending the FTOS with new features.

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Wikipedia