I was going through old math/sketching graph paper notebooks and didn’t want to lose some of the work in them, so I started scanning pages. I took the more comic-y ones and put them up on a server I was testing out, and got a bunch of readers when BoingBoing linked to me. I started drawing more seriously, gained a lot more readers, started selling t-shirts on the site, and am currently shipping t-shirts and drawing this comic full-time. It’s immensely fun and I really appreciate y’all’s support.
https://www.explainxkcd.com/wiki/index.php/LiveJournal
September 30 2005 looks to be the earliest that any xkcd comic was uploaded to the internet