After a question in my SAN switch firmware upgrade article I made a comparison of two downloads of 6.3.1b (one via IBM and one from HP) – the only differences were a file called ancillary and one called EULA.pdf. I used examdiff to find the differences.
All the sub-directories were the same, only the above two files were added in the HP one.
I believe quite strongly that you can use the HP firmwares to upgrade Brocade switches that are branded by other vendors.
At least IBM and normal Brocade ones.
As they are using the very same Brocade firmware that Brocade themself use, it might be hard for the vendors to change the switch that much.
It would be interesting to investigate if other vendors add something to make theirs not, but I have no way of acquiring such a firmware.
The EULA looks like a normal HP standard end user license agreement form. The HP ancillary.txt file contains this: