I still don't know the full history of this pbooru website but I ended up pulling a somewhat larger effort than I thought I would. Turns out this was an attempt to set up a clone of the old ponibooru. The main booru in the fandom before Derpibooru. A good bit of the site's content turned out to be directly imported from there. My knowledge of the site is admittedly rather limited other than I knew that it was a bit of a chaotic place that was shutdown when the owner couldn't afford it (or mentally couldn't handle it. Or he freaked out oddly. One of those). I've also heard that there was some drama as well. From what I've seen does go with what I remember hearing about it. The site had a strange system of meta post over having a forum. Discussion took place within the comments of the site. So you would have these text only or mostly text picture post, charts and meme posing questions to the userbase of the website or starting a dissuasion topic. Though the comments hadn't been imported, the actual meta posts were and the ones I downloaded plus some of the self referential memes do give a pretty good idea on what ponibooru's culture was like along with some early fandom dynamics. I had hoped that some of this was backed up elsewhere but unfortunately from the searches I did it did appear there was a lot that wasn't on Derpibooru. I even found some art most of which was rather lower tier that unless it wasn't properly tagged certainly wasn't on Derpi either. I think most of the art and general pony memes are safe but it's a shame that the last records of what was once a prospective pillar site of the fandom may have been lost.