Are LDAP servers considered databases for the purposes of this site?
I'd personally say so. Just because it's not an RDBMS and doesn't speak SQL doesn't make it not a database.
When the proposal was originally in area 51, before it was renamed to 'database administrators', I put in a few questions referencing noSQL, heirarchical and network databases, and none of 'em got an off-topic vote. (they didn't rise up to the top, but they weren't voted against)