Assuming we're all still talking about multiplayer games... I think you guys need to take a quick look on the main forum page.
In particular, you might be interested in
this thread, which appears to provide a (semi-)realistic way to deal with multiplayer syncing issues.
The concept is simple: trying to sync multiple computers is physically impossible. Even a few milliseconds of lag could cause desync issues, since the order of operations is critically important to DF. Even if you had two identical machines operating on a LAN, you'd
still have enough lag that any attempt for direct multiplayer would eventually desync and fail.
Dfterm, however, uses a remote terminal to view and interact with a remote computer. Think about it: what if you could modify this system to support multiple inputs? It'd be more like a standard server-client architecture. The server would be the
only machine actually running DF - everybody else would pass instructions through Dfterm.
You'd still have a few issues (if one person opens a designation window, nobody else can interact with the system until they've finished), but that could be sorted out once Toady decouples the UI from the underlying game (if he ever does, obviously). Fundamentally, you'd only have
one game of DF running, just with multiple people trying to control it.