Helmet is a neo-grotesque display typeface, currently with a single font. It takes inspiration from Swiss classics like Helvetica and Univers but plays with proportions such as width and x-height to create a unique look and feel. Licensed under the SIL Open Font License, the font is available for free both for personal and commercial use.
Helmet is designed in the open source font editor Birdfont. Birdfont is far from perfect but has worked out all right for this single-font typeface.