Why using Univention for the authentification of this forum

I simply thought it was funny to see a Debian based product managing the authentication for this forum
While Univention is a great and German product (which might be considered as a pleonasm)
I was wondering why OpenSUSE forum don’t use something build on top of SUSE or OpenSUSE ??
At the end, LDAP is also available in OpenSUSE no ?

It isn’t just the forums - it’s the entire openSUSE infrastructure that uses it (bugzilla, obs, and many other services). An actual Identity Provider service was needed, and while sure, running something on openSUSE or SLE would be nice, ultimately, if the software is better supported on Debian, it makes sense to run it there.

LDAP isn’t a single-sign-on protocol. You need SAML or OAuth for that. LDAP would give you a single set of credentials, but it wouldn’t give you a seamless experience between sites that share that SSO infrastructure. (Note: I work in the field of identity management and SSO - this is a field I’ve been in for a long, long time.)

There was some info on the heroes list at https://lists.opensuse.org/archives/search?mlist=heroes%40lists.opensuse.org&q=univention - you might check that out. The forums staff really isn’t involved in that part of the infrastructure (though we certainly support the use of a true SSO solution instead of just requiring users enter their username and password on any openSUSE site they visit - that’s not a great user experience.)