This is seriously one of the most beautiful things I have come across on this site.
If it wasn't already impressive for its originality (Unless, actually, the web is full of '00s-style fake sites and I never found them-), it's really well done, both in its construction and in its storytelling!
As someone else also said, even though I knew how it was going to end, I read the News section in one go. The "secret" post that reveals everything, both in terms of how you have to unlock it No, of course, it's not that I had to read other comments to find out despite it being obvious, of course, no- and for the way it sheds new light on the whole story is really well done.
I had noticed how Kiwi was taking up more and more space in the News section, but I thought the drama was more about the fact that The Newcomer seemed to be sort of stepping over one of the founders. On re-reading the posts, the truth seems almost obvious, yet I had not thought of it-
Again as already mentioned by others, a special note for Lemon's absence until the end, despite being the founder and writer. It was really effective, especially her way of expressing herself at the antipodes of what one had read up to that point from the others.
Having finished exploring the site, I re-read the post set in the present. Of course, at first you don't know who O, L and M are, but once you've read it all, it plays its role very well as an epilogue - For everyone, not just the three of them!
I wasn't part of early 00s online life, but I have years of experience (?) as a lurker, so you've smashed the door of nostalgia feels. Also, I find the description "A love letter to the people who like to show up after it's over." truly wonderful.
Really good job, my compliments!