clientside/os/frisbee.redux subdirectory.
It is normally built as part of the complete Emulab build process,
but there is a Makefile.sa-linux which should work to build
Frisbee independently of Emulab. The tool for creating Frisbee format
disk images is in the clientside/os/imagezip subdirectory.
Likewise, there is a Makefile.sa-linux standalone Makefile.
We also no longer distribute a bootable FreeBSD ISO image with the Frisbee client included. The last such distribution is from July 2008 and can still be found here, but it is based on FreeBSD 6 and is unlikely to boot on any modern hardware. However, with a small amount of work you should be able to build the Frisbee client and embed it in the bootable distro of your choice.