[nine_k]

They have a comparison at the bottom of the page. Some letters are dead ringers, some, like "g", differ significantly.

[tobr]

Except for the ”H”, none of them are particularly similar to Whitney. It would have been more interesting to compare the glyphs to Source Sans. Its ”g” is basically identical to this one.

EDIT: I created such a comparison. See neighboring subthread.

[delta_p_delta_x]

I'd say this is Source Sans. I'm sorry to trivialise Nebula's effort, but this seems much ado about nothing—they warped Source Sans' glyphs to be metrically compatible with Whitney, renamed the result 'Nebula Sans', got a developer and videographer to produce a whole website and mini-documentary on the matter and called it a day.

Excuse me?

[andai]

Reminds me of that Bill Gates quote, "I get the laziest programmer to do the hardest job because he'll find an easy way to do it."