[oneplusone]

I have yet to see an open source font that comes even close to a professional font like Helvetica.

[luminarious]

Inter UI is quite impressive as far as usability goes: https://rsms.me/inter/

[jjeaff]

Roboto is free, and very very close to Helvetica. http://theunderstatement.com/post/11645166791/roboto-vs-helv...

[anoncake]

What's wrong with Nimbus Sans?

[mark-r]

Nimbus Sans was designed to be a complete lookalike for Helvetica. I'm not sure how they got away with it, except that the IP laws protecting fonts are rather weak.

Besides, I don't think it's open source.

[anoncake]

Nimbus Sans is not a lookalike for Helvetica, it is a Helvetica. The visual appearance of fonts is not copyrightable. And it's GPL'd.

[Mirioron]

What does it mean for a font to be GPL? Does it carry the license along into any project you use that font in?

[mark-r]

The GPL version was produced to be included with Ghostscript, which itself is GPL, so that wasn't an issue. I'd be very wary of using it with any other project.

[anoncake]

That sounds like FUD.

[floatboth]

Fira Sans, PT Sans/Serif, Roboto, Noto, Source Sans/Code Pro, Cantarell...

[billfruit]

I thought DejaVu Sans was pretty descent, especially as a terminal font.

[amyjess]

Noto. It feels like having access to an entire professional foundry as a FOSS download.

Though the sans is humanist and not neo-grotesk like Helvetica.

Hell, Noto Sans is available in more weights than Helvetica Neue LT Pro. I've actually found myself wishing that Helvetica Neue LT Pro had a real demi instead of jumping from medium to bold. Noto solves that problem.