The first version of WordPress was released on May 27th, 2003, and meetups all over the world are organizing parties to celebrate the upcoming 10th anniversary.
We'll be meeting to hang out and share stories, see how WordPress has evolved, and give away some swag.
Special 10th Anniversary t-shirts are available for $10 for anyone who's interested. They take about 7 business days to ship, though, so try to place your order by the 15th if you want to have it in time for the party.
If you'd like to read more about the celebrations going on around the world, check out the original announcement.
Note: The official RSVP page is at http://www.meetup.com/WordPress/Seattle-WA/926442/, but you're more than welcome to RSVP here instead. They both work, but we needed to setup both in order to connect with the other cities around the world who are participating.