Hi there!
Elio here from Ura Design, part of the Usability Lab.
I noticed that OTF is using Gotham as it’s primary font for headings. Due to its nature, I’d suspect it might be more appropriate for OTF to use an open source typeface licensed under an Apache or SIL open font license instead of a proprietary typeface like Gotham.
In fact, there is probably a good alternative without changing the looks of the website presence. The typeface Montserrat is visually quite similar to Gotham and is popular among open source projects without being overused like Open Sans (The Fedora Project uses Montserrat as well).
This is an example comparing the OPEN TECHNOLOGY FUND wordmark in both typefaces:
You can find Montserrat here for a closer look:
While this might be a very minor thing at the first sight, I’d think that it’s a low hanging fruit which would align OTF’s visuals with its values it stands for.
I’d love to get your feedback on this!