The following has shamelessly been copied from a message sent to all community moderators and was written by Kevin Chang. Please vote before December 10th whether you want Sustainability SE to participate or not. Upvote either the yes or the no answer below.
The end of the year is upon us, and here in Stack Land, that can only mean one thing: it's time for Winter Bash 2015!
Winter Bash is a fun, lighthearted event we run every year as a way of celebrating the many amazing people who make our communities awesome. It's open to any Stack Exchange site that chooses to participate.
During Winter Bash, users earn virtual hats by completing certain tasks. They're sort of like badges, but they're more visible and less permanent. Hats can be "worn" on users' avatars just about anywhere avatars show up on the network. Here's an example of what some hats looked like last year, taken from the network leaderboard:
Of course, we’re rolling out an all-new assortment of hats for this year's event, as we have in the past.
This year's event will start on 14 December 2015 and run up to and including 03 January 2016. Users will be able to see all the hats they've earned on http://winterbash2015.stackexchange.com. That site will also have an FAQ to explain how things work.
Individual users who don’t want to participate, don’t want to see hats, and/or are generally anti-hat will have an “I hate hats” option available. And just like last time, at the end of the event, all hats will go back into storage.
The only visual change to the Stack Exchange sites themselves will be the presence of the hats and the “I hate hats” button in the footer.