Default Sans is your standard neo-grotesque. It’s subtly different from most other generic sans serif. The goal was to not draw attention to itself. It gets out of the way so the words can be clear, neutral. Default Sans is reliably solid and somewhat familiar, that’s the appeal. Download/view a PDF specimen.
In the download: 18 styles (9 weights in upright & italic) in otf/ttf/woff2 formats. License to make stuff!