Moderustic

Switch a Moderustic label from Regular to Bold and it keeps its width. Tural Alisoy drew every style to the same width, so a tab that turns bold on hover or a menu item marked as active will not shove its neighbors sideways, and that property alone is the reason to pick it for interface work.

There are 6 weights, Light at 300 up to Extra Bold at 800, no italics. Latin with its extended accents is covered, with Greek and Cyrillic beside it.

Then comes the feature list, which is long for a UI sans: 20 stylistic sets, discretionary ligatures, old style and lining figures, subscripts and superscripts, fractions. We have seen few interface families carry that many sets. A team building a brand on top of its app could go hunting in them for a letter that sets the product apart from its rivals.