I think I was 10 years old (so that would be 1998)... It was a site run by a Catholic school, actually a discussion forum of the school's website. A couple of the teachers were the admins and moderators. It had a purely social side, but there was also places to discuss Catholicism, morality, and more. I was not a student at that school, but a Catholic friend of mine told me about the site and non-students of the school were welcomed.
I was very active there. And I had a LOT of questions but the two teachers were VERY embracing, very welcoming. Being a theology junkie even then, I loved the site. I was even one of 3 or so kids (and by far the youngest) who was made a helper (not really a mod); I was given the ability to make a post disappear from public view - it was still there, the 2 staffers could see it, but not the public. We helpers simply handed it over to the mods to do with as they determined. This was necessary because sometimes there was rudeness but also because the site was sometimes attacked by anti-Catholics or even by perverts eager to present porn to Catholic children (sick, huh?)
Sadly, one of the two teachers resigned.... and soon the other felt overwhelmed... and the discussion forums were eliminated.
.