I know it isn't strictly Indigo-but here is a hack to install Prophet on an
Indigo2 R10000 (IP28 mainboard). It should work with other new machines
(Octane, Fuel, Onyx10k, etc.)

If you just run the installprophet script, it will error out with the message
"You don't appear to have an operating system compatible with running Prophet
software."

This is not the case, though. The problem is that the script checks for IRIX
by running "uname", and in the 64-bit ARCS machines the output of uname is
IRIX64.

The hack is simple-just open "installprophet" in an editor and, where it says

"ULTRIX|IRIX|OSF1);;"

add IRIX64, to read

"ULTRIX|IRIX|IRIX64|OSF1);;"

Prophet then installs, and works great.