First contact with the Zahl was made on stardate 51268. The U.S.S. Voyager was transiting Zahl space following an attack by the Krenim.
From first indications the Zahl possess a level of technology equal to that of the Federation. They are very friendly with respect to all except the Krenim. The Zahl consider the Krenim a nuisance species that travels their systems making threats on other spacecraft.
One of the civilizations destroyed by the Krenim time weapon ship. Destruction of the Zahl race was responsible for a 98% restoration of the Krenim Imperium. Presumably restored following the ships destruction. NOTE: Events occured in alternate timeline.