Back in mid-to-late 90s I was addicted to an online trivia game called Cosmo's Conundrum. It was a Java applet that had a large core of players, chat capabilities and cash prizes. The game went through some iterations and the parent company eventually folded, but many of the players stayed in touch, attempted migrations to different trivia platforms, and are still connected via Facebook. Many friendships and marriages came out of this simple game.
I've always wanted to rebuild it, but never quite had the time for it. Was even able to snag the original domain name years later, but even that went nowhere. In a few years my own kids will be the same age I was when I played it, it is an odd thought.