Fira Sans is an open-source typeface designed by Erik Spiekermann with additional contributions from Carrois Type Design. It was created for the Firefox OS in 2013 and shortly thereafter released as open-source. Fira Sans is heavily based on Spiekermann’s FF Meta and features a contemporary humanist design with open apertures and a large x-height. The Fira family is still under active development and currently features nine weights with matching italics as well as a monospaced version.
Font research done for you.