In the olden days, Linden Lab would put a list of events announcing its anniversary everywhere: on their webpage, on the forums, in-world, everywhere.
This year we have to rely upon my good friend SignpostMarv Martin’s information of what’s going to happen on what used to be one of Second Life’s largest and most-attended events. Under the theme of “History”, here are a few scattered links about what the celebrations are going to be:
https://wiki.secondlife.com/wiki/SL4B
http://signpostmarv.name/sl4b/press-release.html
A partial list of events: