OMAC 0 in EAX cipher I am reading Rogaway's original paper on EAC, page 7, where the MAC function is an OMAC with a 0.

Iwata´s web page only refers to versions 1 and 2 of the OMAC cipher. So which algorithm is used for OMAC 0?
The OMAC version used by EAX is OMAC1, which is equivalnent to CMAC. The zero you're talking about is probably the zero in $\operatorname{OMAC}^0_k$. This does however not distinguish different algorithms but it displays the tweak value. The tweak itself is simply prepended to the message before OMAC1 is applied.

This is explained in figure 1:


  Algorithm $\operatorname{OMAC}^t_K(M)$
  (50) return $\operatorname{OMAC}_K([t]_n | M)$


so t is encoded in $n$ bits before being put in the OMAC function.