But don't you find there are a lot of non-canon violating things untold?

Nope, not really. Or at least, not so many that I'm interested in. But for the most part, nope.

To be honest, I don't really have much of an opinion on fan fiction. I don't actually have much of an opinion on people using my characters in fan fiction. For that matter I barely have an opinion on "slash" fiction (although I still find the idea of Good Omens slash fiction fairly mindboggling) (er, and Knight Rider slash fiction. I think that Knight Rider slash fiction is pretty weird, to be honest).

As long as people aren't commercially exploiting characters I've created, and are doing it for each other, I don't see that there's any harm in it, and given how much people enjoy it, it's obviously doing some good. It doesn't bother me. (I can imagine a time and circumstances in which it might. But it doesn't.)

...I don't honestly mind if you stick (for example) Shadow or the Marquis De Carabas into a story intended for your friends, and not for commercial exploitation. I'd rather you put a note at the end saying who the characters belonged to, which most fan fiction people seem pretty good about doing anyway. But I'd hope you'd see it as a privilege and not a right.

Neil Gaiman (neilgaiman.com journal), April 8th 2002

He's cool with it. Bless him. Which looks very much like I'm trying to convert you to be all LitFicYay! - I'm not, 'cause I get that the areas of discomfort are very personal, and I know a lot of people are troubled by the idea of lit fic. But this put my mind at rest, because my concern would have been if he'd said he found it upsetting/a violation/whatever, rather than out of an inherent dislike of lit-based fic. So this is just in case anyone else was in the same mental space as me.

('cause, yes, it's ALL about me. Always.)

(Dare someone to write me Crowley/Kit)

Any good Joyce/Giles fics out there?

Signed,
Just rewatched Band Candy

the Potterverse contains enough throwaway lines and minor characters scattered about for it to feel incomplete. It is possible that this could be read as a critique of her writing.

Yes and no. Especially in genre/future/AU fiction I like authors who can create a world that seems new and convincing at the same time. I'd say that in a lot of these, there are exactly these elements - characters whose stories are key to establishing the legitimacy and realism of the world, but who aren't central to the story the author is telling. I like seeing those looser bits in a story. Those are ripe for fanfic, IMO. I can more easily see an author taking issue with fanfic that alters or contradicts the paths of her main characters than those who play with the edges. I'm not really up on it, but my take is that Anne McCaffey's dragon stories have inspired a lot of this around the edge sort of fic.

OTOH, maybe those are the sort of thing that a writer can later claim they meant to go back to and pick up? Personally, I'd think it the highest compliment that I'd managed to create a world that seemed so true that people wanted to explore it on their own.

(Dare someone to write me Crowley/Kit)

....tempted

You know, on the litfic front, I'm finding more and more that the books I read as a child offer new places for fic. When I was younger, I always used to wonder what happened to the characters after. With fanfiction, I find that I can write those stories. It completely blindsided me, at first, when I saw Narnia fiction. But I love the notion now. Narnia, The Dark is Rising, the Murray family from Madeleine L'Engle--all those stories I loved as children I'm re-exploring as an adult, and now I realize I want to write stories about them too.

In my perspective, I think it's kind of my respect to the writer that I loved their work so much I couldn't get it out of my head.

When I was younger, I always used to wonder what happened to the characters after. With fanfiction, I find that I can write those stories. It completely blindsided me, at first, when I saw Narnia fiction. But I love the notion now. Narnia, The Dark is Rising, the Murray family from Madeleine L'Engle--all those stories I loved as children I'm re-exploring as an adult, and now I realize I want to write stories about them too.

I always did this as a kid. With TV shows, too. I didn't know it was proto-fic; just that I liked the storied so much I didn't want them to end. I just wanted to climb in through the lines of text and walk around in that world for a while.

Now I get a chance to, with fanfiction, yo. I love fandom.

Litfic is really it's own literary genre. Foe is a retelling of Robinson Crusoe from Friday's POV. Ditto Wide Sargosso Sea as a retelling of Jane Eyre from the story of the madwoman in the attic. It's gotten kind of rampant in the last several years, but it's fairly commonplace now. Updike even redid The Scarlet Letter.