-reified generics: From what I've seen, the Ceylon guys have done a good job of implementing this and they make flow-sensitive typing possible. Without out, th

-reified generics: From what I've seen, the Ceylon guys have done a good job of implementing this and they make flow-sensitive typing possible. Without out, the benefits of union types don't fully materialize. See http://ceylon-lang.org/blog/2015/04/19/observable/ http://ceylon-lang.org/blog/2015/04/19/observable/ - problem of null: Ceylon uses union types to union between the class in question (ex String) and Null, which is a type separate from Object. Therefore, the typesystem enforces this. And yes, Ceylon has the exists operator, which means you can do if (exists stringOrNull) to instanceof/cast at the same time. - elegant APIs - With regard to file I/O: https://modules.ceylon-lang.org/modules/ceylon.io/1.1.0/doc https://modules.ceylon-lang.org/modules/ceylon.io/1.1.0/doc - language spec - Ceylon's is much more detailed: http://ceylon-lang.org/documentation/1.1/spec/html_single/ http://ceylon-lang.org/documentation/1.1/spec/html_single/