explain xkcd was originally a blog, created in July 2009 by Mike and mostly written by Jeff, who posted explanations of xkcd comics, occasionally helped by his friend Berg and by Mike. The blog gradually developed a significant following, and much interaction happened in the comments, especially for complex comics, where commenters pieced together all parts of Randall's epic comics which would have taken way too much time for Jeff to do alone.
Eventually, several people in the comments starting calling for the blog to be converted to a wiki, allowing its followers to chime in with corrections and even full explanations when Jeff would have less time. While other, xkcd, wikis had been attempted before, none had managed to gain enough traction. Explain xkcd, on the other hand, had a sizable community of commenters, which gave it better chances of pulling it off. In December 2011 Jeff trialled a new project where people could submit explanations for old comics (published prior to the start of the blog), which he posted with due credit. After a while, Jeff decided to make the switch and on 10 July 2012 this wiki was created. The announcement was made on the blog a few days later. The wiki has been gradually collecting explanations for all 1360 xkcd comics and everything xkcd-related.
As usual with all small wikis, spam quickly became prevalent, and although it was kept out of sight of most visitors through the efforts of diligent editors (especially Lcarsos and Davidy22), spam-fighting was, for a while, the bulk of work that was being performed in the wiki, which demoralized most editors and nearly killed the community. Finally, by the end of February 2013 Jeff installed the ConfirmEdit extension (before that, Extension:ReCAPTCHA was being used, to little avail), which instantly killed off nearly all spam activity on the wiki. Users rejoiced, and the community quickly regained its health and even surpassed previous levels of activity, fueled by new users drawn by particularly complex comics such as 1190: Time and 1193: Externalities.
As the wiki became more and more popular, the number of old unexplained comics kept shrinking. The 1000th comic explanation was created on 9 April 2013, and by 8 June 2013, all previous comics had been explained, which led to a change in focus on the wiki activity, towards expanding the incomplete explanations.
Unfortunately, the growing popularity of explainxkcd brought increased stress to the server, which began to fail quite often due to the high volume of visits. Jeff added donation buttons to the sidebar in an attempt to collect enough funds to migrate to a better server. Eventually, in late August 2013 an advertising strategy was devised which has been in place since.
- Note: The explain xkcd logo was created by User:Alek2407.