This is yet another "unstable" release, but you should be able to
replace 0.2.0 and 0.3.0 with it without issues (hopefully).

So what's new in 0.4.0?  More inline functions have been removed/
fixed, allowing compilation on OpenSolaris.

Please visit

http://bitwi.se/software/ruby/character-encodings/

for more information.

Enjoy!