[MichaelGG]

Ruby's Japanese heritage is probably why it handles encodings like that - I think there were multiple encs it had to deal with at once or something. Also Unicode doesn't completely handle all kanji in that there's some that have an old style not available in Unicode. But maybe that's not relevant.

[aidenn0]

Unicode now handles all the Kanji in JIS. I wouldn't be surprised if Ruby predated that. It almost certainly predates good library support for all the Kanji in JIS.

[GolDDranks]

I think the problem isn't whether it handles all the Kanji in JIS – it does. But the problem is that JIS at the time was so common that it didn't necessarily make sense to settle exclusively for then-less-used UTF-8. That would make re-encodings necessary at interfaces and on IO.

[steveklabnik]

Ruby encoding stuff changed a lot over its history; it was one of the big changes from 1.8 to 1.9.