[behnamoh]

For fck's sake, please stop using this font. I know Apple started the trend but even they went back to sane alternatives. The narrow lines of this font are a torture to the eyes.

[elicash]

I think this is just plain Helvetica, with weight at 300 rather than 400.

Apple used to use Helvetica, and even an ultra thin version of it, but I wouldn't say they started the trend of using Helvetica.