Dylan and Ruby aren't that similar, except to the extent of their use of "end" as a delimiter (inherited from Algol through Pascal). In Dylan, methods do not belong to objects, and can dispatch on more than one of their parameters. Ruby, on the other hand, uses more traditional Smalltalk-style OOP.

Dylan isn't necessarily better designed than Ruby (though I think it is), but rather it's less eccentric than Ruby and more targeted at static compilation. It has type declarations the compiler can use to eliminate dynamic dispatch, it has proper lexical scoping allowing variables to be allocated to registers, etc.