The different architecture exe's are as follows (so always use the one that matches your system):
TomEE.amd64.exe = 64bit OS TomEE.ia64.exe = Itanium OS TomEE.x86.exe = 32bit OS
The only difference to Tomcat is that they ship with 'like named' binaries, but in sub-directories - Or offer separate downloads for your OS. We just modified the batch files to detect your arch-type and use the correct binaries. Everything is all in the 'bin' directory so we only have a one zip fits all approach.
Definitive documentation can be found here:
http://commons.apache.org/proper/commons-daemon/procrun.html