Fira Sans

Named after the Martian word for 'freedom': Mozilla commissioned Spiekermann's studio to build Firefox OS's face and open-sourced it. A light, wide-aperture humanist sans superb at small mobile sizes, it also hosts Fira Code among programmer favourites. Eight weight pairs, variable, condensed siblings - interface to advertising. Warmer than grotesques, lighter than geometrics, tailor-made for 'friendly tech'; slightly behind Inter in UI mindshare yet equal in craft.

Carrois drew Fira Sans with full Central-European sets - Czech, Polish, Turkish - and early Vietnamese support; governments from Brazil to the EU have written Fira into brand specs. When pairing with Fira Code, keep the mono in the terminal and return to Fira Sans for prose.

Licensing footnote: early Fira builds carried GPL-with-font-exception; the repo now unifies under OFL - match your archive to the file's own LICENSE, and don't conflate FiraGO (a separate continuation by SANSEI-ZO) in records. At the UI level its 300 is one of the few light cuts that survives body use; around 350 reads best on dark themes.

Mobile apps, content platforms, civic and edtech (public sectors in Brazil and Europe run on Fira), code-brand adjacency. Picks: 300/400 text, 500 UI, 700 heads.

Licence：SIL Open Font License 1.1

The dominant permissive licence for open fonts: free commercial use, modification, embedding and redistribution. Its core duties are that derivatives stay under OFL without the Reserved Font Name, the licence text travels with the files, and the fonts themselves are never sold standalone. Works typeset with them belong wholly to you.

Standard OFL 1.1 duties.