EDE was ported to FreeBSD and packages are available for x86 and x86_64 computers. You can either install EDE from packages, build it from ports or compile and install it manually.
Packages are available on the official FreeBSD pkg mirror so you don't have to adjust anything. Just install EDE.
FreeBSD versions up to 9 use the old pkg tools by default whereas version 10 uses pkg-ng. Since FreeBSD 8.4 however, you can install the new pkg-ng as well.
If you use 8.4 or 9.x and are in doubt execute the following line:
cat /etc/make.conf
Should the file contain the string WITH_PKGNG=yes, your system uses pkg-ng.
In both cases setup X11 the way you want it and install EDE using the right package management tool.
pkg_add -r ede
pkg install ede
You can build EDE from ports on FreeBSD. Make sure you have the most current ports:
portsnap fench portsnap update
Then change into the directory for EDE (/usr/ports/x11-wm/ede) and issue make.
The ports dialog will let you choose if you wish to compile EDE with or without HAL support.
Alternatively you can of course follow the generic building procedure, too: InstallingFromSource.
You can either use a graphical login manager or start it using startx. In the later case edit the .xinitrc file in your user's home directory so that it just launches EDE. The line for that is the following:
exec startede