Board Thread:The Panopticon/@comment-188432-20130110025213/@comment-1046-20130111175021

Here's a free sans serif font with the sort of clean look I'd prefer: Nexa

However, although the site says it's free, I'm not sure whether its license is compatible with cc-by-sa.

Another alternative to consider might be. That's the font used in the BBC logo, and Wikipedia says that in its original form it's public domain, so licensing concerns don't apply.