Inter
Sphinx of black quartz, judge my vow
Free Helvetica alternatives
Drawn by Max Miedinger and Eduard Hoffmann at Haas in 1957, and the twentieth century default for anything that wanted to look neutral.
What a Helvetica substitute has to get right
The apertures have to close. A face with open, angled terminals reads as humanist however tight you set it, and the even grey Helvetica makes at text size comes from the aperture rather than from the weight.
The one in this archive
One entry, because one is the honest answer. A face is listed here only if the substitution would survive a designer looking at both.