[Tellurium][1], 17 bytes
=

    µHello, World!~^

Well, this is pretty easy to explain.

- `µ` starts reading the string
- `~` stops reading the string, and stores it in the selected cell.
- `^` outputs the selected cell's value, which is currently "Hello, world!"

# Alternate version (5 bytes)

This one uses the preinitialized variable `!o`, which expands to "Hello, World!".

    µ!o~^




  [1]: http://m654z.github.io/Tellurium/