Where do you find this? I know a _lot_ of embedded systems run NetBSD too... There are also a lot of embedded systems that run custom real-time OSs. Be sure to realize that Linux Is Not UniX.
Jon.
I stand corrected. Much of the older embedded systems were run with a NetBSD or RTOS on them. But Linux is becoming the OS of choice to migrate these embedded systems to. Go google "embedded linux" and read through he volumes of information. It makes for some very enlightening and eye opening reading.
One of the more interesting articles: http://www-128.ibm.com/developerworks/linux/library/l-embl.html and http://www-128.ibm.com/developerworks/library/l-embdev.html
Also the following site it pretty interesting: http://www.embeddedlinuxinterfacing.com/
Enjoy the reading.