>I think where he's drawing the idea of Quarians on Rannoch from is
>from one of my favorite sequences in Mass Effect 3 during which they
>reveal some of the Geth's perspective on history, most of which has
>been lost or sanitized by the Quarians including the fact that there
>were Geth sympathizers during the Morning War who fought to protect
>their Geth friends/servants. I assume the ME fan fiction sub-genre
>he's referring to relies on the premise that some of them survived.

Kinda-sorta.

Basically, once it turned out that the geth were misunderstood, as opposed to a collection of hive mind Reaper-worshipping sumbitches, a number of people started thinking: "Huh. Assuming the geth were at least trying to conduct their war in as moral a way possible without allowing themselves to be genocided, it would actually have been very, very hard for them to kill EVERY quarian on Rannoch, assuming that they also took steps to preserve Rannoch's biosphere. Therefore, it is entirely possible there's been a remnant of the quarian people there, quietly rebuilding for the past three centuries."

This isn't true, of course, in ME canon. But it's an interesting enough idea that a lot has been done with it. In particular, Gregg Landsman's "Glorious Shotgun Princess" has used it to good effect; that story features a small (three million or so) quarian nation still living on Rannoch as of the time of ME2, and those quarians are less than enthused about repatriating the flotilla, who 1) outnumber them six to one, and 2) are the descendants of people they view as idiotic war criminals. The flotilla in turn regards them with a mix of suspicion (verging on 'all y'all are race traitors') and jealousy (the 'indigenous' quarians have perfectly functioning immune systems and can walk around without encounter suits just fine.)

-Merc
Keep Rat