Faketown was one of the first realtime interactive chat applications. We thought that the web should be realtime rather than call and response. So we dove into the realm of socket servers with shockwave multiuser server a.k.a "SMUS".
Learnings
Our first web application was routinely hacked but we partnered with the users that found exploits to help us refine our product. That said, we quickly learned that we could not build a real economy if users could hack their way to the top.