Helvetica Neue Light with @font-face .. legal? [closed]

If you are just referencing the users system fonts then the licensing requirement is on the User.

If you are providing the font then you (or your client) will need to licence the Font -- even if it's a free font there will likely be some form of licence.

@font-face uses two forms of reference: LOCAL which references the user's system font and URL which effectively uses a copy of a font which you provide and as there is very little point in using the @fontface rule if you aren't going to provide the font then it's almost certain that you'll need to actively obtain a licence.

for example:

@font-face {
  font-family: myHelveticaLight;
  src: local("Helvetica Neue Light"),
       local("HelveticaNeue-Light");
}

Here you are only referencing a user's installed system font and therefore have no have responsibility for obtaining the licence.

In the following example you are also providing a fallback copy of the font so you must have actively obtained a web licence for that font (or rather your client or the website owner will need to)

@font-face {
  font-family: myHelveticaLight;
  src: local("Helvetica Neue Light"),
       local("HelveticaNeue-Light"),
       url(HelveticaNeueLight.ttf);
}

Apple pays for its system fonts, so the inclusion of a font in Apple's operating systems doesn't tell you much. That particular font is owned by Linotype and sold for profit. A quick Google tells me fonts.com offers Neue Helvetica Light as a Web font, so you might take a look there.

Just took a look, and its actually Adobe who owns it, and they sell it for money. So, my best guess is no, you couldn't legally use it for free. I have no idea if Adobe licenses it, though. Maybe you could try and find one that's licensed for web use, and is similar to Helvetica?