Google and Adobe's pan-CJK open font

Hangul has 24 letters, but it doesn't have "24 glyphs" in essentially any digital font in widespread use. First of, those letters sometimes form digraphs and trigraphs that essentially are letter-like in practical use (to the point where some have their own keys on the keyboard). Further, multiple letters are grouped into syllabic blocks (also morphemic in practice, since blocks often happen to map to morphemes) in a number of different arrangements based on how the letters tetris together[1]. Unicode contains code points for both the individual letters and the pre-composed blocks (in fact, you can use a neat little formula to map from the former to the latter). Fonts usually contain glyphs for both as well; almost no software implementation attempts to compose them from combining characters at runtime.

That means font designers/implementors have more than 10k blocks to take care of - because of their regularity (since they *do* compose down to letters) it's not quite a Han-scale problem, but it means some similar challenges (the stroke density for more complex blocks is more similar to hanja than to individual Latin letters, say).

And as rahulsundaram points out Koreans do still sometimes (rarely now) use hanja, so they need to fit nicely aesthetically.

1 = http://upload.wikimedia.org/wikipedia/commons/8/82/Hangeu...