Keywords are reasonable easy to type (I'm much faster typing plain text without special characters), simple to auto-complete and read very well. For example, they could have used something like "to" instead of "->", eg:

    "Hello World" to std.out

That's just an idea I had on the spot, not sure how it would play out. But I think this stream programming would actually lend itself well to some sort of literate syntax.

This is indeed what I meant. Typing "end" is, for me at least, way faster than typing "}". The reason is that "end" does not require modifier keys, and that all the letters are relatively accessible in the middle of the keyboard. (If you don't speedtype, this might not make as much a difference.)

Thanks for the elaboration. I might even agree about the typing, even though e.g. `end' requires one keypress more than } for me. But I find that punctuation stands out more. From a practical point of view, I prefer reading Haskell's

  \arguments -> body

to Scheme's

  (lambda (arguments) (body))

because it stands out more. What gives me as the reader an even better hint without getting in the way, is indentation. That's why I prefer that to e.g. curly braces for reading. (Writing, especially in non-programming editors, like a webform, is easier with explicit markers like `end' or } though.)