Full Unicode is supported nearly everywhere but HN these days. ;P

Also GitHub has long supported :emoji-name: expansions for those that want to limit UTF-8 in their git commits, and for those on operating systems without dedicated emoji soft keyboards. (In recent Windows 10, Windows+. and Windows+; bring up the emoji keyboard. It's great.)

I've seen projects require emoji as prefixed commit type descriptors: a bug emoji like ant is more interesting than FIX:, a wrench more interesting than TOOLING/SUPPORT:, etc. A neat benefit of that is it leaves the commit types as one character width lining things up nicely and leaving more room for meaningful text in the commit header.

I tend to do something similar with my personal repositories though not nearly as systematic.