JRuby is great, the only issue with existing projects is trying to convert all the gem dependencies that use native code over to java. Popular ones like Hprico

JRuby is great, the only issue with existing projects is trying to convert all the gem dependencies that use native code over to java. Popular ones like Hpricot have jruby equivalents, but unpopular ones like ruby-gsl or image_science have no hope.