If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
Others have already explained what it stands for and provided a link; it may be worth adding that the author of that blog is also known on LW as Yvain, who once upon a time was one of the best and most prolific LW contributors; his particularly highly rated posts include one on the notion of "disease", one about metacontrarianism, one clarifying what it means when a model says something is almost certainly true, one on efficient charity, one introducing prospect theory, one about buying houses, one about Schelling fences, one about the worst argument in the world. (He's still one of the best but participates rather little.) He's also the guy who does the annual Less Wrong survey.
Yeah. I actually have read a fair bit of Yvain's blog. I just had never thought of abbreviating its name before, so I blanked when I saw "SSC."
That said, I am sure a lot of other readers of this thread may not have known about Yvain's contributions.