it is my pleasure to announce the x509 0.7 series, which contains a major revision of the API (using a map instead of lists for extensions, general and distinguished names, …). The release 0.7.1 is already merged into the opam-repository, and users of x509 have been updated to comply with the new API. I wrote a blog post about this release – https://hannes.nqsb.io/Posts/X50907. I’m happy to receive feedback, either in this topic, via eMail, or via social media.
EDIT: the API documentation is available at http://mirleft.github.io/ocaml-x509/doc/x509/X509/index.html