1) I am using xubuntu and cgminer 3.7.2 - can I use this xi with this?
I believe only the sgminer version of cgminer supports xintensity.
Kalroth cgminer does as well
Does anyone know who came first? Kalroth cgminer or veox sgminer? Are there any other popular versions?
Looks like it was kalroth first and sgminer took it up from there, and perhaps both developing in parallel now.
Kalroth came first as veox mentions taking some functionality from that branch in their work. I think one of the advantages of sgminer is that development is continuing whereas cgminer has left scrypt behind.