The most legitimate use for this is for top-level namespaces, which need to be short or they'll junk up your code like crazy. jQuery already took $, and Underscore took _. Maybe 木, ϗ, _⃗, 个, î, 人, Ǝ (not ∃, that's illegal!), ℵ, 二, ℜ, 龍, ℕ, 八, Δ, 大, ʃ, ː, 卐, or as mentioned below, λ? ˀ is probably too obnoxious though.
For no particularly good reason, ☺ and ☠ are illegal. I think the Plan9 strategy of considering non-ASCII characters as identifier characters by default is probably a better one than changing the language grammar every time the Unicode standard revs.
For no particularly good reason, ☺ and ☠ are illegal. I think the Plan9 strategy of considering non-ASCII characters as identifier characters by default is probably a better one than changing the language grammar every time the Unicode standard revs.
(As mentioned in another comment, http://canonical.org/~kragen/setting-up-keyboard.html https://github.com/kragen/xcompose. The Chinese I copied and pasted from http://www.mdbg.net/chindict/chindict.php?page=radicals though.)