Soekris Engineering manufactures the SoekrisNet4501 and SoekrisNet4521 which seem very interesting as compact, low-cost BxNode and CxNode platforms. These are 486-class embedded systems with enough RAM to run a complete *nix OS.
As of Sept 2002 this is a "hacker's" platform; there is no shrink-wrapped software solution you can install on here. If you have a Soekris and you are developing for it, the Soekris mailing list is immensely useful.
Pebble Linux is a 40MB distro designed for embedded-style hardware, such as Soekris boards.
Here is a "starter kit" for a net-booting Debian Linux on a Soekris box: http://www.innercite.com/~mike/soekris/ (broken link)
(Note: the NoCat distro has been discontinued.)
ChuckHarrison: As a newbie, when I installed the starter kit to netboot from my Red Hat 7.3 host, I had to deal with these issues:
- if you are running ipchains, make sure you accept dhcp, tftp, rpc portmap, and nfs traffic from the Soekris to your host
- you'll have to start the dhcpd and nfs services somewhere (e.g. rc.local)
- make sure the contents of /nfsroot/debian/etc/network/interfaces are valid for the Soekris ethernet port you are booting over, eth0 in my case. Otherwise "ifup -a" will disconnect you during initialization.
I strongly recommend watching the boot process with a sniffer like ethereal. An ethereal rpm is on the Red Hat disks, or you can download it.