I'm evaluating PKI solutions for my client, and among other more technical attributes I'd like to be able to report a few marquis users of each solution.
Many projects list well-known users or link to media releases or whitepapers, but I can't seem to find any such list on openxpki.org (am I blind?) even though it seems to be a fairly mature (or at least long-lived) project.
Guessing you're not going to find any marquee users. From the download page, they're still strictly in beta : "The OpenXPKI Project has not published formal releases so far."
Leave the question open for a couple of days - someone here might be using it in production and might be quite happy with. You might be able to get a solid endorsement. I just wouldn't hold my breath.
Have you contacted their dev team so see if they have any non-NDA writeups that they could publish or at least share with you?