Thanks for your response. Personally I fall into the "strings are arrays of bytes" camp (which is also shared by Go). A difference between my view and that of the Go designers is that I don't feel that it is important to support Unicode by default and am perfectly happy to assume that every character corresponds to a single byte. Obviously that makes internationalization harder, but the advantage is that strings are much simpler to reason about. For example, the number of characters in the string is simply the length of the string. I would be fine having a separate Unicode string type in the standard library for those instances when you really need Unicode; this design makes the common case much simpler at the expense of making the rare case harder. I also don't see that mutability is such a huge deal unless you absolutely insist that your language support string interning.