@Vergil - Targeting civilians by itself does not qualify, as anyone in the military will tell you (collateral damage, partisan activity)
Are you sure? I understand if this is the case for war crimes, but deliberately targeting civilians certainly isn't self-defense.
But I fully agree it was a genocide, as did Drew Karpyshyn, even if later writers did their damnedest to never mention it again.
Yeah, some writers may try to tone it down as much as possible, but the way the war was described previously, it matches the definition of genocide quite well.
"Genocide is the systematic destruction of all or part of a racial, ethnic, religious or national group via the a) Killing members of the group or causing serious bodily or mental harm to members of the group; c) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part; d) Forced migration"
Wether the Geth actually managed to kill all Quarians or not and which of those aspects they are guilty of is irrelevant.