The great open-source shepherd that is Fedora ships WenQuanYi Micro Hei by default, and the moment it hits actual Korean text the glyphs pile up on top of each other. Looks like absolute garbage. See:

Emoji support on Linux is kind of crippled. Most guides tell you to install a bunch of fonts, and the result is still your emoji rendered in that ugly black-and-white style. Low-effort, honestly. The fix is to find an emoji font that plays nice with Linux. SegoeUIEmoji, bundled with Windows since 8, is one option. The other one I’m covering today is Emoji One.

Firefox just updated to 44.0, and for Linux users that means a new problem. Fonts look like garbage. Like this: